President Trump signed a bill aboard Air Force One Monday upgrading the birthplace of civil rights icon Dr. Martin Luther King Jr. to a national historic park.

Trump signed the bill into law on Air Force One while in Atlanta, Georgia, alongside Dr. King’s niece, Alveda King, and the civil rights leader’s nephew, Isaac Newton Farris Jr., according to a statement from the White House.

The law would expand the boundaries of Dr. King’s birthplace in Georgia to make it a national historic park, allowing the National Park Service to preserve a greater area of land.

The new boundaries of the area would include the Prince Hall Masonic Temple, which used to be the headquarters of Dr. King’s historic civil rights organization, the Southern Christian Leadership Conference.

The legislation Trump signed was sponsored by Rep. John Lewis (D-GA), a Democrat who boycotted attending the opening of the Mississippi Civil Rights Museum because the president had been in attendance.

Before the president approved the legislation, the national historic site encompassed Dr. King’s birthplace, his final resting place, and the church where he was baptized.