"Darkness and denialism can hide much but they erase nothing," Biden told guests in the ornate, marble edged Indian Treaty Room next to the White House, before signing the proclamation.
One of the monument sites is his funeral location, Roberts Temple Church of God in Christ, in Chicago.
Signs erected at Graball Landing since 2008 to commemorate Till's killing have been repeatedly defaced by gunfire.
Any future vandalism would be investigated by federal law enforcement rather than local police, according to Patrick Weems, executive director of the Emmett Till Interpretive Center in Sumner, Mississippi.
He screened a film recounting the lynching, "Till," at the White House in February.
Persons:
Joe Biden, Emmett Till, Mamie Till, Kamala Harris, Bradley, Biden, Patrick Weems, Emmett, Thomas Edison's, Wheeler Parker Jr, Till's, Parker, Donald Trump, Ron DeSantis, Christopher Benson
Organizations:
White, Rights, Temple Church of God, National Park Service, of, Republican, Florida Governor, Mobley Institute
Locations:
theIndian, Washington , DC, Chicago, Money , Mississippi, Mississippi, Tallahatchie, Sumner , Mississippi, America, Washington, Summit , Illinois