However , historian Gerald Prokopowicz writes that , while it is not clear that sculptor Daniel Chester French intended Lincoln 's hands to be formed into sign language versions of his initials , it is possible that French did intend it , because he was familiar with American Sign Language , and he would have had a reason to do so , that is , to pay tribute to Lincoln for having signed the federal legislation giving Gallaudet University , a university for the deaf , the authority to grant college degrees .