Here's another couple:
Copied from the UCLA site:
Other Digital Sheet Music Collections
> Lester Levy Collection of Sheet Music - Johns Hopkins University > African American Sheet Music - Brown University
> Historic American Sheet Music - Duke University > 19th-century California Sheet Music - UC Berkeley > Music for the Nation - Library of Congress
> Florida Sheet Music Collection - University of South Florida > Center for Popular Music - Middle Tennessee University > Charles H. Templeton Sheet Music Collection - Mississippi State University > Nineteenth-Century American Sheet Music Digitization Project - University of North Carolina at Chapel Hill > Keffer Collection of Sheet Music, ca. 1790-1895 - University of Pennsylvania
> Performing Arts in America, 1875-1923 - New York Public Library > Sam DeVincent Collection of Illustrated American Sheet Music, ca. 1790-1980 - Smithsonian Institution