On Barack Obama’s final day in office, Cassandra Metzger stood on a sidewalk facing the White House uncertain of her future.

She had arrived with a group of friends in the early morning to show gratitude toward the outgoing president, one day before Donald Trump would be sworn in as his successor.

They hoisted a sign that read “Thank you President Obama: Your grace still echoes above the noise” on a busy street that lines Lafayette Square, a public park situated north of the White House now barricaded by a chain-linked fence as part of preparations for Trump’s inauguration.

Cars zipping by the group expressed their approval with a honk of their horns, as some rolled down their windows to pump a fist in the air or offer a thumbs-up. This city voted for Hillary Clinton over Trump by 92.8% to 4.1% in November’s election. Several of those walking through the area, many of them tourists, cheered upon catching a glimpse of the pro-Obama banner.

Metzger, a Washington resident, deemed her attachment to Obama personal. His landmark healthcare law was a life-saving policy for Metzger, who said she had suffered from a chronic illness for 17 years and before the Affordable Care Act’s passage paid high premiums due to her pre-existing condition.

“Obamacare was a very big deal for me personally,” she said.

“[It] saved me literally thousands of dollars per year, so I’m very emotional about it, and I’m very terrified right now, frankly.”

Metzger said she had no plans to watch Trump, who has vowed to repeal Obama’s healthcare law, take his oath of office on Friday. She will instead spend the day readying her modest apartment to host guests for the Women’s March on Washington, a highly publicized event expected to draw as many as 200,000 protesters on Saturday.

“My friends have agreed they’ll push me in my wheelchair if necessary,” said Metzger, who is holding out hope that Republicans might still improve upon the existing healthcare law rather than dismantle it.

Standing at her side was Amy Lewis, an acupuncturist who has treated Metzger and who organized the gathering of Obama supporters. Lewis, who lives in Maryland, said it was a simple thought born from her desire to thank the president and his family as they depart the White House after eight years.

“I’ll miss his grace under fire, I’ll miss his fairness, I’ll miss his inclusion for everyone in this country,” Lewis said of Obama.

Like several other supporters, she had posted an event on Facebook for those who might wish to join her outside the White House on Obama’s final day. Although the space directly outside the president’s home was walled off for Trump’s inauguration parade, Lewis was joined by others on the sidewalk across the park with similar ideas – some of them strangers.

Jennifer Breaux: ‘He’s been a fantastic leader, a great role model, and just a generally beautiful human being.’ Photograph: Sabrina Siddiqui/The Guardian

They included Jennifer Breaux, a law student at Howard University who brandished her own sign reading: “Yes you did”, a play on Obama’s 2008 campaign slogan “Yes we can”.

It was a quiet sendoff for a president who will leave office with one of the highest approval ratings of any previous occupant of the Oval Office.

A larger rally, dubbed “Thanks Obama”, was expected to draw thousands in south-west Washington later in the day. That effort also stemmed from a mere Facebook post, but due to its spike in popularity transformed into a paying event for which tickets quickly sold out.

But that didn’t stop others from perching themselves as close to the White House as possible to bid farewell. “Thank you, Mr President,” read one sign, while another saluted his deputy with the words: “Say it ain’t so, Joe.”

“I just want to share my gratitude and appreciation for the last eight years,” said Breaux.

“He’s been a fantastic leader, a great role model, and just a generally beautiful human being.”

Asked if she was concerned by the tone of his successor, Breaux said she did not wish to get “bogged down by the negativity”.

While feeling that any rational person would be “heavily concerned” by the tenor of Trump’s campaign, Breaux said she planned to heed Obama’s advice: “Let’s not panic until we have to.”

“I’m in law school now, studying civil rights law,” she added with a wry smile. “So I feel like I’ll be prepared.”

Lewis said she was “depressed and disappointed and terrified for our country”, but similarly opted for a positive approach.

“I think we’ve taken a significant step back, but as Dr Martin Luther King said, ‘The arc of the moral universe is long, but it bends toward justice.’”

Her husband, Ken Jenkins, said the setback for Obama supporters in no way undermined how they viewed his tenure. Jenkins, a former NFL player, ticked off the expansion of healthcare coverage, economic recovery, and revival of the US auto industry among the achievements for which the outgoing administration would be remembered.

“He did it against a do-nothing Congress who, frankly, from a black person’s point of view, they didn’t want that young, intelligent black man telling them what to do,” Jenkins said.

“That’s how I feel about it – I think that’s how a lot of black Americans feel about it.

“He did it against all odds,” Jenkins said. “That’s what I hope his real legacy ends up being.”

Jan Percival flew from California to the gathering in DC: ‘My heart is broken that he’s leaving.’ Photograph: Sabrina Siddiqui/The Guardian

Across town from the White House, as many as 700 were expected to fill an event space reserved for the official “Thanks Obama” event that grew organically from a Facebook post to a decidedly greater ordeal.

A few hundred milled in and out of the building, known as Arena Stage, situated a stone’s throw away from the US Capitol. They swayed to live music performed by local artists and cheered a group of hula dancers in a nod to Obama’s birthplace of Hawaii.

Jan Percival flew across the country, from her home of San Diego, California, to take part in the evening’s festivities. While she had initially hoped to get closer to the White House, Percival said she was happy to take in Obama’s last day with her “tribe”.

“My heart is broken that he’s leaving, and I just really wanted to express my personal thanks to him for his leadership and the sacrifice of his family,” she said. “The man is incredible.”

Unlike many other Obama fans, Percival said she would attend Trump’s inauguration while in town after receiving a ticket from a friend who worked on the organizing committee.

“You know what, it’s history,” she said. “I’m not happy about it, I’m not celebrating … but I’m still going to go.”

Percival noted, however, that she planned to wear a “pussy hat” – a knit hat with little ears donned by women in reference to leaked audio of Trump boasting about sexually assaulting women – “in silent protest”.

Organizers sought to keep the spotlight on Obama, rather than dwelling on the next commander-in-chief. Walls were covered in white poster board, where attendees left messages thanking Obama for his service.

Attendees write thank you messages to Obama. Photograph: Sabrina Siddiqui/The Guardian

A representative from a local performing arts collective, One Love Massive, told the crowd the purpose of the gathering was to reflect on the historic nature of Obama’s presidency.

“When I was growing up, the idea of a black president was almost an anathema,” the man said.

“My children were born in an era where a black president was just a matter of fact.”