Three former presidents came together to honor Congressman John Lewis at his funeral in Atlanta, Georgia, on Thursday, completing a week of memorial services for the longtime lawmaker and civil rights icon.

Former President Barack Obama delivered a rousing eulogy celebrating Lewis' life. "He, as much as anyone in our history, brought this country a little bit closer to our highest ideals," Obama said.

He addressed the issue that defined Lewis' legacy, calling on Congress to act on voting rights. "Let's honor him by revitalizing the law he was willing to die for," Obama said, to an ovation at the funeral. He added, "John wouldn't want us to stop there. Once we pass it, we should keep marching to make it even better," listing new provisions like automatic registration and making Election Day a national holiday.

Thursday's private funeral came after one week of ceremonies in Alabama, Georgia and Washington, D.C.

The arc of Lewis' life and civil rights legacy will once again tie into the history of Ebenezer's former pastor Martin Luther King Jr., a close ally whom Lewis called his leader.

Lewis died July 17 at age 80.

George W. Bush, the first among the living presidents to pay homage to Lewis, said Americans live in a country that is better today because of the late congressman.

"John Lewis always looked outward, not inward. He always thought of others. He always believed in preaching the gospel, in word and in deed, insisting that hate and fear had to be answered with love and hope," Bush said. "John Lewis believed in the Lord. He believed in humanity, and he believed in America."

Bush also noted that while he and Lewis had their disagreements, such disagreements are cornerstones of a democracy.

"In the America John Lewis fought for and the America I believe in, differences of opinion are inevitable elements and evidence of democracy in action," Bush said. "We the people including congressmen and presidents can have differing views on how to perfect our union while sharing the conviction that our nation, however flawed, is at heart a good and noble one."

In his eulogy, former President Bill Clinton referred to Lewis as "a man I loved for a long time." He reminisced about Lewis' humanity, and how this made him a great, as well as a good man.

"I think it's important for all of us who loved him to remember that he was, after all, a human being," Clinton said. "John Lewis was many things, but he was a man," Clinton later added.

He ended his remarks by saying that Lewis "was here on a mission" to advocate for civil rights, Clinton said, and he noted that Lewis "left us with marching orders" in his op-ed in the New York Times, published on the day of his funeral. In the piece, Lewis urged Americans to continue to get into "good trouble." The former president suggested that Americans honor this request: "Salute, suit up, and march on."

In an essay published in The New York Times on Thursday, Lewis implored younger generations to keep fighting, telling them, "Now it is your turn to let freedom ring.”

He asked that the essay be published on the same day as his funeral, which is being held Thursday at Ebenezer Baptist Church in Atlanta.

The late congressman wrote that in the final days of his life, he was "inspired" by the protests against racial injustice and police brutality that were spurred by Floyd's death at the hands of a Minneapolis police officer, and said that movement is what drove him to visit Black Lives Matter Plaza in downtown Washington, D.C., even though he was admitted to the hospital the day after his visit on June 7.

"Emmett Till was my George Floyd. He was my Rayshard Brooks, Sandra Bland and Breonna Taylor," Lewis wrote, noting that "[Till] was 14 when he was killed, and I was only 15 years old at the time."

The late congressman reflected on the lessons he learned from Martin Luther King Jr. and encouraged young Americans to exercise their right to vote, writing "the vote is the most powerful nonviolent change agent you have in a democratic society."

"When historians pick up their pens to write the tory of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war," Lewis wrote. "So I say to you, walk with the wind, brothers and sisters, and let the spirit of peace and the power of everlasting love be your guide."

Lewis is being laid to rest after a week of celebrations in Alabama, Georgia and Washington, D.C.

(The Associated Press, CBS News contributed to this report.)