The George Washington Carver - Booker T. Washington (GWC-BTW) Half Dollar was signed into law by US President Harry S. Truman on September 21, 1951. The coin's authorizing legislation was actually an amendment to the previous Act that authorized the 1946-51 Booker T. Washingon Birthplace Memorial Half Dollars; Truman signed that bill into law as well (on August 7, 1946).
Proceeds from the sales of the coin were to be used by the Booker T. Washington Birthplace Memorial and the George Washington Carver National Monument Foundation to "oppose the spread of communism among Negroes in the interest of national defense." So, not for direct financial support of the two Monument/Memorial sites.
The Carver National Monument was established by the US Congress in 1943; the Booker T. Washington Birthplace Memorial was created as a private memorial, with the effort led by Sidney Phillips, in 1940.
The National Park Service (NPS) took over responsibility for the Carver Monument's acreage in June 1951; it assumed responsibility for the BTW Birthplace Memorial (renamed the Booker T. Washington National Monument) in April 1956.
Following the GWC-BTW half dollar's first-year release, the Director of the National Park Service, Conrad Wirth, presented examples of the new coin to Secretary of the Interior, Oscar Chapman, and Assistant Secretary of the Interior, Dale Doty. A photo opportunity of numismatic proportions!
(Note: The NPS is an agency within the US Department of the Interior.)As the coin was not necessarily a direct fund raiser for the NPS, the coin's presentation ceremony within the US Department of the Interior was mostly symbolic, tying into the NPS' recent resonsibility assumption for the George Washington Carver National Monument vs. kicking off a sales drive.
Conrad Wirth Presents GWC-BTW Memorial Half Dollars - March 1952
(Image Credit: Harry S. Truman Library & Museum, Oscar Chapman Scrapbook. Public Domain.)Note: Conrad Wirth is in between Secretary Chapman (right) and Assistant Secretary Doty (left).1951 George Washington Carver - Booker T. Washington Half Dollar

For other of my posts about commemorative coins and medals, including more stories about the GWC-BTW half dollar, see:
Commems Collection.