(CNN) Civil rights icon and US Rep. John Lewis of Georgia was released from the hospital Sunday evening with a "clean bill of health," his spokeswoman said.
"All tests have been completed," Brenda Jones said in a statement. "He thanks everyone who shared their thoughts, prayers and concerns during his stay."
Lewis became ill Saturday on a flight to Atlanta, CNN affiliate WSB-TV reported, quoting unnamed sources.
Lewis, 78, has represented Georgia's 5th Congressional District, which includes much of Atlanta, since first being elected in 1986.
In February 2011, President Barack Obama presented Lewis with the Presidential Medal of Freedom, the country's highest civilian honor.
The long-serving Democrat was a young activist and leader of the Student Nonviolent Coordinating Committee when, in March 1965, he joined forces with Martin Luther King Jr. to lead a voting rights march out out Selma, Alabama.
But as the nonviolent demonstrators approached the Edmund Pettus Bridge, on their way to the state capital in Montgomery, they were confronted by heavily armed state troopers and local police. When the march refused to turn back, protesters were set upon and beaten.
The images from "Bloody Sunday" -- and Lewis, who was photographed under assault and suffered a fractured skull -- helped galvanize support for the Voting Rights Act, which was signed into law by President Lyndon B. Johnson months later.