Former President Barack Obama was honored Sunday night in Boston as he accepted the John F. Kennedy Profile in Courage Award, joining past presidents such as Gerald Ford and George H.W. Bush in receiving the distinction.

Obama told the crowd at the John F. Kennedy Presidential Library and Museum that congressional lawmakers should show political courage and not repeal the Affordable Care Act, the health care law that was the signature legislative achievement of his administration.

Last week, House Republicans approved a health care bill designed to replace the law also known as “Obamacare.”

Critics of the Republican bill say it amounts to a huge tax cut for wealthy Americans at the expense of coverage for those with low and modest incomes.

House Republicans voted more than 50 times to repeal the Affordable Care Act during Obama’s tenure.

In his 45-minute remarks, Obama said he hopes lawmakers recognize that “it actually doesn’t take a lot of courage to aid those who are already powerful, already comfortable, already influential.”

Obama praised the courage of freshman lawmakers who voted for the Affordable Care Act, knowing that it might put their seats and political careers at risk. “These men and women did the right thing,” Obama said. “They did the hard thing … and most of them did lose their seats.”

The Democrat has made few public appearances since leaving office in January, and he has avoided mention of his Republican successor in the White House, even as President Trump has criticized the previous administration numerous times while moving to undo many of Obama’s initiatives.

Obama and former first lady Michelle Obama arrived earlier Sunday at the presidential library for dinner.

The Profile in Courage award is named for a 1957 Pulitzer Prize-winning book by Kennedy that profiled eight U.S. senators who risked their careers by taking principled though unpopular positions.

This year marks the 100th anniversary of President John F. Kennedy’s birth.

Among the long line of guests who made their way down the red carpet into the library for the event Sunday night were members of the Kennedy family, members of Congress, former Obama staffers and celebrities including former late-night talk show host David Letterman.

U.S. Rep. Joe Kennedy III, a Massachusetts Democrat, said Obama earned the award by meeting many challenges that faced him during his presidency.

“It’s about understanding the challenges we face as a country and as a planet and mustering the political will to do what is right even if what is right at that moment isn’t necessarily popular,” said Kennedy, a harsh critic of the Republican health overhaul plan.

In selecting the former president for the award, the John F. Kennedy Library Foundation lauded Obama for expanding health security to millions of Americans, which opponents of the bill passed by the House on Thursday argued could be lost if it becomes law. The bill faces an uncertain future in the Senate.

“President Kennedy called on a new generation of Americans to give their talents to the service of the country,” said Caroline Kennedy, the late president’s daughter, in announcing the award in March.

“With exceptional dignity and courage, President Obama has carried that torch into our time, providing young people of all backgrounds with an example they can emulate in their own lives.”

Caroline Kennedy presented the award to Obama.

The Washington Post contributed to this report.