Government Departments get appropriations from Congress. Public donations for specific purposes are limited in scope.
"Citizens who wish to make a general donation to the U.S. government may send contributions to a specific account called "Gifts to the United States."
https://www.fiscal.treasury.gov/public/gifts-to-government.html "CNN reports that “federal regulations prohibit agencies from accepting donated funds unless Congress grants authority to the agency to accept the donation. Without congressional authorization, donated money is deposited into the general fund of the Department of Treasury.”
We contacted the Department of Treasury to find out if documentation for any such deposits is publicly available and have yet to hear back."
