Hillary Clinton. AP Photo/Kevin Lamarque, Pool, File The first tweets of 2016 presidential candidates range from GOP frontrunner Donald Trump telling his followers in 2009 to watch his appearance on "The Late Show" with then-host David Letterman, to Ohio Gov. John Kasich assuring the world know he's "using Twitter for the first time."

Other candidates similarly used their first tweet to announce that they were now using the social-media platform.

These tweets and others gained renewed attention Monday because the day marked Twitter's anniversary.

Here are the first tweets — unless they've been deleted prior to Monday — from some of the 2016 presidential candidates:

Trump spoke of himself in the third person in his first tweet:

Former Secretary of State Hillary Clinton thanked the creators of the 'Texts from Hillary' meme, which was her initial Twitter profile image:

Sen. Bernie Sanders' first tweet —unsurprisingly — hit on an economic issue: Credit-card interest:

Kasich might have had one of the most basic entrances to the social media in the platform's history:

Cruz was simply confused:

Sen. Marco Rubio, a now-departed presidential candidate, dedicated his first tweet to former Minnesota Gov. Tim Pawlenty. It didn't get much interaction:

Sen. Lindsey Graham, another ex-2016 candidate:

Retired neurosurgeon Ben Carson had plenty of engagement with his inaugural tweet:

—Dr. Ben Carson (@RealBenCarson) February 15, 2013

2012 GOP presidential nominee Mitt Romney looks as if he may have deleted some tweets prior to this one:

US President Barack Obama's first tweet was about the Iraq War:

You can search the first tweets of any Twitter user here.