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.

Smithsonian's National Museum of American History, Washington

Smithsonian National Museum of African American History and Culture / Freelon Adjaye Bond/SmithGroup

National Museum of American History - Carltonaut's Travel Tips

Smithsonian National Museum of African American History and

Smithsonian National Museum of American History Renovation di SOM - Skidmore, Owings & Merrill

Ultimate Guide To The National Museum of American History

Smithsonian overhauls American History Museum – Orange County Register

National Museum of African American History and Culture (NMAAHC

National Museum of African American History and Culture, Washington DC

American History Museum Exhibit Explores Pop Culture

Smithsonian National Museum of American History