Ulysses Grant worked closely with Congress and used federal troops to support legislation. This unity led to the remarkable changes during reconstruction.
Truman appointed a committee on civil rights in 1946 and gave a special message to Congress in Feb 1948 requesting key elements of later civilrights legislation.
Kennedy finally submitted a general civil rights bill to Congress in June 1963.
Johnson backed US v. Mississippi in 1965 and took federal action to enforce it.
Kennedy was limited by large numbers of republicans in congress who saw him as too pro-civilrights.