To designate former United States Route 66 as "America's Main Street" and authorize the Secretary of the Interior to provide assistance.

[AI summary unavailable — showing source text] Designates portions of the highway formerly designated as U.S. Route 66 that remain in existence as "America's Main Street." Directs the Secretary of the Interior to: (1) establish the Office for the Preservation of America's Main Street; and (2) designate National Park Service officials stationed at locations convenient to the States in which a portion of Route 66 is located and interested persons in such States to perform Office functions. Requires the Office to: (1) support efforts of State and local public and private persons and entities in such States to preserve Route 66 by providing technical assistance, participating in cost-sharing programs, and making grants and loans; (2) act as a clearinghouse for communication among Federal, State, and local agencies and private persons and entities interested in the preservation of Route 66; and (3) assist such States in determining the appropriate form of and establishing and supporting a non-Federal entity or entities to perform the Office's functions after it is terminated. Authorizes the Office to: (1) enter into cooperative agreements; (2) accept donations; (3) provide cost-share grants; (4) provide technical assistance in histo…