National Museum of American History

A wooden bar (6-1/8" x 2" x 3/4") is attached to a flat wooden handle (17-7/8" x 2" x 1/8") by nine wooden pegs. By the 17th century, draftsmen used T-squares to help them draw horizontal lines.

The Smithsonian National Museum of American History's New Exhibits

Inside the National Museum of African American History and Culture

National Museum of American History (Smithsonian): The District

The Smithsonian National Museum of American History Semi

National Museum of American History in Northwest - Tours and Activities

Smithsonian National Museum of American History Renovation – SOM

Smithsonian National Museum of American History - Cinnabar

Smithsonian National Museum of African American History and Culture by David Adjaye: Commemorating America's Black heritage - RTF

130+ National Museum Of African American History And Culture Stock Photos, Pictures & Royalty-Free Images - iStock

Smithsonian National Museum of American History Renovation di SOM

File:Smithsonian National Museum of American History - Seinfeld

David Adjaye on the National Museum of African American History