To John Lewis, the vision Donald Trump has for America is all too familiar.

He grew up in rural Alabama, when schools were segregated and the public library wouldn't give him a library card because only whites could borrow books.

Trump's talk of a wall along Mexico's border, deportations, mosque closings and special identity cards all sounds like a future Lewis thought was in the past, the civil rights leader told supporters gathered Wednesday at the African American Museum in Philadelphia.

"They're trying to take us back to another period, trying to make it harder and more difficult for people to participate in the democratic process, and we must not allow it," said Lewis, a Democratic congressman from Georgia who was one of the "Big Six" civil-rights leaders in the 1960s. "We've got to win this election. We've got to win, I'm telling you."

Lewis visited the museum as the keynote speaker of Americans for Democratic Action's commemoration of the 1948 Civil Rights Plank, a historically unprecedented commitment to racial justice made during the Democratic National Convention, held that year in Philadelphia.

The Southern delegations so strongly opposed the plank that some walked out when it was adopted. Still, Hubert H. Humphrey, ADA's founder who would go on to be elected vice president under President Lyndon Johnson in 1964, made a persuasive case for civil rights in a speech urging fellow Democrats to "get out of the shadow of states' rights and walk forthrightly into the bright sunshine of human rights."

But Wednesday, Lewis and Rep. Keith Ellison, D-Minnesota, who also spoke at the commemoration, didn't dwell on the civil rights movement's successes since 1948.

Instead, their talk turned into a rally of sorts, with both men urging the audience to unite to defeat Trump — although neither mentioned the GOP presidential nominee by name.

"If you supported Bernie, thank you. Thank you for invigorating the program. Thank you for enlightening our democracy. Thank you for making the best and most inclusive platform that this Democratic Party has ever seen," Ellison said. "But when we stare that mass of ugly in the face, we got to come together."

Retired NBA Hall of Famer Kareem Abdul-Jabbar called on the audience to improve education, which he called "the great equalizer," in poor and minority neighborhoods.

Lewis implored the crowd to vote — and work to get others to the polls — because in his belief, a Trump presidency, especially on the immigration issue, could erode decades of civil rights progress.

"As the pope spoke at a joint session of the Congress, he said we all are immigrants. And I take the position that there's no such thing as an illegal human being," Lewis said. "We have work to do. We have to save America and help save the planet, and help create what Dr. King called a beloved community, where we respect the dignity and the worth of every human being. That's our calling."

He added: "We can make this country what it should be. And if we get it right, we can serve as a model for the rest of the world."