U.S. Rep. John Lewis was hospitalized Saturday after falling ill on a flight to Atlanta.

The civil rights hero, 78, was on a flight from Detroit on Saturday when he started feeling dizzy and sweaty, an aide said.

He was later hospitalized for “routine observation” in Atlanta. “He’s resting comfortably and expects to be released tomorrow,” the Democrat’s office said in a statement Saturday evening.

Lewis is known as a pivotal figure in the civil rights movement.

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From a hardscrabble childhood in Alabama, by the time he was a teen he had embraced the Rev. Martin Luther King Jr.'s nonviolent resistance to segregation.

Later, he became a student activist, taking part in the Nashville lunch counter sit-ins, the 1961 Freedom Rides, the 1963 March on Washington and the Bloody Sunday march in 1965, where he was beaten in the skull by a state trooper in Selma, Alabama. Lewis has represented Georgia's 5th Congressional District since 1987.