Many U.S. presidents are measured by their oratorical eloquence, but Donald Trump's first 100 days in the Oval Office (he hits the mark on Saturday) might be better judged by his Twitter output.

His tweets have moved markets, advanced conspiracy theories, attacked his own party and ultimately helped define his fledgling presidency.

The U.S. president actually uses two accounts, but his activity via @realDonaldTrump outpaces the official @POTUS account, which he tends to use for more diplomatic pronouncements.

Here's a look at some of his most memorable — and consequential — tweets as president so far.

Day 1

It all begins today! I will see you at 11:00 A.M. for the swearing-in. THE MOVEMENT CONTINUES - THE WORK BEGINS! —@realDonaldTrump

Trump marked the morning of his inauguration with a tweet referencing "the movement" that helped him ride a populist wave to the presidency.

Day 4

A photo delivered yesterday that will be displayed in the upper/lower press hall. Thank you Abbas! <a href="https://t.co/Uzp0ivvRp0">pic.twitter.com/Uzp0ivvRp0</a> —@realDonaldTrump

A few days after the inauguration, Trump proudly tweeted a framed photo of the inauguration crowd. Sharp-eyed Twitter users, however, noticed that the caption under the picture said "Jan. 21." (The inauguration was Jan. 20.)

The error came amid the White House claiming Trump's inauguration drew the "largest audience," both in person and around the world, of any U.S. inauguration. The claim was disproved with aerial photos and statistics, but it led Kellyanne Conway, counsellor to the president, to coin a new euphemism — "alternative facts" — to defend the administration's claims.

Day 5

I will be asking for a major investigation into VOTER FRAUD, including those registered to vote in two states, those who are illegal and.... —@realDonaldTrump

even, those registered to vote who are dead (and many for a long time). Depending on results, we will strengthen up voting procedures! —@realDonaldTrump

On his fifth day in office, Trump announced he would order a probe of supposed massive voter fraud, a claim that even Republicans on Capitol Hill have said is not backed by evidence.

Although Trump defeated Hillary Clinton in the election by winning the Electoral College 304 to 227, Clinton won the national popular vote by nearly three million more votes — a fact Trump dismissed by making the unsubstantiated allegation that millions of votes were fraudulent. His repeated allegation that up to five million illegal immigrants voted has been widely rejected.

Day 6

The U.S. has a 60 billion dollar trade deficit with Mexico. It has been a one-sided deal from the beginning of NAFTA with massive numbers... —@realDonaldTrump

of jobs and companies lost. If Mexico is unwilling to pay for the badly needed wall, then it would be better to cancel the upcoming meeting. —@realDonaldTrump

One week into office, Trump was already embroiled in a foreign-policy spat. Mexican President Enrique Pena Nieto did indeed cancel his meeting with Trump after the U.S. leader tweeted the above ultimatum and signed an executive order to move forward on constructing a border wall with Mexico, a key campaign pledge.

Mexico has refused to foot the bill on the wall. Trump later said cancelling the meeting was a mutual decision. By late April, Trump had backed down on demands for immediate funding for the border wall in order to pass a budget measure. He continued to insist, however, that the wall will eventually be built.

Based on the frequency of his tweets, Trump appears to spend a lot of time on his smartphone. (Joshua Roberts/Reuters)

Day 12

Everybody is arguing whether or not it is a BAN. Call it what you want, it is about keeping bad people (with bad intentions) out of country! —@realDonaldTrump

Trump's executive order on Jan. 27 suspended travel for refugees and citizens from seven Muslim-majority countries: Iran, Iraq, Syria, Sudan, Libya, Yemen and Somalia. But the order was reportedly never properly reviewed by Justice Department officials; Homeland Security was also given little forewarning or guidance.

The result was chaos and confusion at airports and immigration checkpoints. A federal appeals court would go on to stop the ban from being enforced.

Day 16

Just cannot believe a judge would put our country in such peril. If something happens blame him and court system. People pouring in. Bad! —@realDonaldTrump

On Feb. 3, James Robart, a federal judge in Washington state, ruled that the executive order on travel be suspended temporarily "on a nationwide basis." Trump lashed out at Robart, warning the U.S. should "blame" the Seattle judge for his ruling if it put the country in "peril."

It brought to mind a Trump attack last June on another judge with whom he disagreed: Gonzalo Curiel, a U.S.-born citizen of Mexican heritage. Trump called him a "Mexican" judge and questioned Curiel's impartiality while presiding over the Trump University fraud case. Lawsuits alleged that real estate seminars offered through the now-defunct school cheated people out of thousands of dollars. In April, Curiel approved a $25-million agreement to settle the fraud claims.

Day 19

My daughter Ivanka has been treated so unfairly by <a href="https://twitter.com/Nordstrom">@Nordstrom</a>. She is a great person -- always pushing me to do the right thing! Terrible! —@realDonaldTrump

Nordstrom announced on Feb. 2 that it was dropping the Ivanka Trump clothing brand from its stores, citing dwindling sales for the president's daughter's fashion line. The move came amidst a social media campaign (#GrabYourWallet) to boycott Trump-related products to express outrage with the new government.

Presidential counsellor Kellyanne Conway later gave the clothing line a free plug, exhorting Fox News viewers: "Go buy Ivanka's stuff." Conway was reprimanded, but the endorsement apparently worked — the Associated Press reported a 771 per cent hike in sales for the label on the e-commerce platform Lyst in February compared to the previous year.

Day 25

The real story here is why are there so many illegal leaks coming out of Washington? Will these leaks be happening as I deal on N.Korea etc? —@realDonaldTrump

The night before this tweet, Trump fired his former national security adviser Michael Flynn after reports he misled Vice-President Mike Pence about making contact with Russia's ambassador to the U.S., Sergey Kislyak, prior to Trump taking office. Trump directed his anger at the leaks seeping out of his administration, which exposed Flynn's talk with Kislyak and led to his downfall.

A good chunk of Trump's time on Twitter has been spent refuting criticism of his executive orders on immigration. (Kevin Lamarque/Reuters)

Day 28

The FAKE NEWS media (failing <a href="https://twitter.com/nytimes">@nytimes</a>, <a href="https://twitter.com/NBCNews">@NBCNews</a>, <a href="https://twitter.com/ABC">@ABC</a>, <a href="https://twitter.com/CBS">@CBS</a>, <a href="https://twitter.com/CNN">@CNN</a>) is not my enemy, it is the enemy of the American People! —@realDonaldTrump

Escalating his attacks on the press, Trump branded the mainstream media the "enemy of the American People." The New Yorker noted that Vladimir Lenin and Joseph Stalin used similar terminology to stigmatize opponents of the Bolshevik revolution. In an interview with NBC's Meet the Press, Republican Senator John McCain criticized Trump's anti-media attack, saying: "That's how dictators get started."

Day 43

How low has President Obama gone to tapp my phones during the very sacred election process. This is Nixon/Watergate. Bad (or sick) guy! —@realDonaldTrump

Citing no proof (and misspelling "tap"), Trump made a stunning early-morning claim about his predecessor, Barack Obama, saying the 44th president had ordered phone lines at Trump Tower in New York City to be bugged during the election campaign.

Trump later revealed to Tucker Carlson of Fox News that he based his unsubstantiated claim on news reports, although it is unclear which report ever alleged Obama ordered a wiretap. At a House intelligence committee hearing into Trump-Russia ties on March 20, FBI director James Comey attempted to put the matter to rest. "We have no information that supports those tweets," Comey testified.

Arnold Schwarzenegger isn't voluntarily leaving the Apprentice, he was fired by his bad (pathetic) ratings, not by me. Sad end to great show —@realDonaldTrump

Just over an hour after accusing Obama of wiretapping, Trump took aim at another familiar target: actor-turned-California-governor Arnold Schwarzenegger. Trump was responding to news that Schwarzenegger would not return to host another season of The Celebrity Apprentice, citing "baggage" left by Trump, whom he replaced.

Trump, who despite becoming president remained executive producer of the program, had slagged Schwarzenegger in January for his poor ratings.

Day 50

We are making great progress with healthcare. ObamaCare is imploding and will only get worse. Republicans coming together to get job done! —@realDonaldTrump

As reports swirled about the inability of House Republicans to unite on a repeal and replacement bill for the Affordable Care Act, also known as Obamacare, Trump attempted to tamp down anxieties.

Repealing Obamacare without a replacement would have increased the number of uninsured Americans by 18 million within the first year, according to the nonpartisan Congressional Budget Office. In the end, Trump's conservative replacement, the American Health Care Act, failed to garner enough support to appease both hardline conservatives and more moderate Republicans. Trump ultimately pulled the bill from a vote on the House floor on March 24.

Trump's tweets have moved markets, advanced conspiracy theories, attacked his own party and ultimately helped define his fledgling presidency. (Reuters)

Day 59

James Clapper and others stated that there is no evidence Potus colluded with Russia. This story is FAKE NEWS and everyone knows it! —@realDonaldTrump

Hours before the first day of a public hearing by the House intelligence committee investigating Russian meddling in the U.S. election, Trump posted early-morning tweets dismissing the Russia story.

Although former director of national intelligence James Clapper has said there was no direct evidence of collusion with Russian officials, House Democrats maintain there is enough circumstantial evidence to warrant the investigation.

Day 69

The Freedom Caucus will hurt the entire Republican agenda if they don't get on the team, & fast. We must fight them, & Dems, in 2018! —@realDonaldTrump

Venting his frustration with the fractious nature of the current Republican party, Trump went after members of the House Freedom Caucus, threatening to thwart their re-elections in the 2018 mid-terms as retribution for their role in sinking his health-care replacement plan.

In doing so, he risked alienating the more than 30 ultra-conservative members of the Republican bloc, whose votes he'll need in order to pass any upcoming legislation. Congressional experts said Freedom Caucus members likely brushed Trump's threats off as empty threats, saying their seats appear safe in 2018.

Day 78

Congratulations to our great military men and women for representing the United States, and the world, so well in the Syria attack. —@realDonaldTrump

On April 6, the U.S. fired 59 Tomahawk missiles at a Syrian government airfield. The reason for the order? Trump said he had been moved by images of children killed by suspected chemical weapons widely believed to have been unleashed by Syrian President Bashar al-Assad.

Although the attack was praised by members of both parties, it marked a turnaround from the administration's previous line that unseating Assad was not a priority. The action drew a backlash from Trump's alt-right supporters, which was concerned the isolationist "America First" presidency was veering towards the kind of elite, "globalist" mindset that the far right abhors.

Day 80

Congratulations to Justice Neil Gorsuch on his elevation to the United States Supreme Court. A great day for America! <a href="https://twitter.com/hashtag/SCOTUS?src=hash">#SCOTUS</a> <a href="https://t.co/8KGFSk8BFj">pic.twitter.com/8KGFSk8BFj</a> —@realDonaldTrump

The confirmation of Neil Gorsuch to fill the Supreme Court seat left vacant after the death of Antonin Scalia was celebrated as one of Trump's biggest achievements in his first 100 days.

The road was rocky, though, as Democratic senators vowed to filibuster the vote on Gorsuch's nomination. The Republicans subsequently invoked the "nuclear option," a change in precedent that for the first time blew up the delay tactic by requiring only a simple majority of 51 votes to advance the nomination. It marked a significant shift in the character of the Senate as a chamber with a strong minority.

Day 81

North Korea is looking for trouble. If China decides to help, that would be great. If not, we will solve the problem without them! U.S.A. —@realDonaldTrump

On April 6, the president met with Chinese President Xi Jinping at Trump's Mar-a-Lago estate in Florida. Trump said he reiterated that he wanted China to crack down on North Korea's hostilities as the rogue state continued to test-fire missiles. If China would not help, Trump said the U.S. would "go it alone" to eliminate the North Korean nuclear threat.

The U.S. president later told the Wall Street Journal that during their meeting, his Chinese counterpart gave him an impromptu seminar on the complexities of the North Korean-Chinese relationship and that "after listening for 10 minutes, I realized it's not so easy" to resolve the nuclear crisis.

Day 95

Canada has made business for our dairy farmers in Wisconsin and other border states very difficult. We will not stand for this. Watch! —@realDonaldTrump

Canada's dairy sector rose like cream to the top of Trump's trade hit list following his "Buy American, Hire American" announcement in Wisconsin.

The president said Wisconsin and New York state dairy producers were being squeezed out by what critics described as the Canadian dairy industry's protectionist rules for supply management. Wisconsin dairy farmers, for their part, told CBC News they don't blame Canada for the hard times, saying the real problem is overproduction and a global glut of milk.

Day 97

I received calls from the President of Mexico and the Prime Minister of Canada asking to renegotiate NAFTA rather than terminate. I agreed.. —@realDonaldTrump

Trump spent months slamming the North American Free Trade Agreement (NAFTA) as a "disaster," but backed off from a threat to pull the U.S. out of the deal after talking to the leaders of Canada and Mexico.

Only hours before this tweet, Trump officials had told reporters the president was preparing to draft an executive order to initiate the process of exiting NAFTA. Trump said he is now willing to renegotiate, but left open the possibility of withdrawing at a future date if he decides his condition for "a fair deal for all" is not met.