This bill directs the U.S. Postmaster General to issue a commemorative postage stamp honoring the late Congressman William Lacy Clay Sr., a Missouri representative who served in the House for 32 years from 1969 to 2001. The stamp would be issued in the standard first-class mail denomination and sold beginning as soon as practicable after the bill becomes law. Clay Sr. was a founding member of the Congressional Black Caucus who championed major civil rights legislation, helped pass the Family and Medical Leave Act, and sponsored nearly 300 bills that became law during his decades in office. The bill, sponsored by Representatives Bell, Smith of Missouri, Carson, and Graves, recognizes his significant legislative legacy and contributions to advancing equality and opportunity for marginalized communities. No specific funding is required, as commemorative stamps are self-funded through their sale by the Postal Service.