Linen postcard of the General Motors Building in Detroit, Michigan — its limestone tower and matching laboratory and convention hall wings rising above a boulevard busy with period automobiles and pedestrians. Designed by architect Albert Kahn and completed in 1922, the GM Building was for decades the company's world headquarters and one of the largest office buildings on earth, a monument to Detroit's rise as the capital of the American auto industry (the complex survives today as Cadillac Place, home to Michigan state offices). A young woman named Vera mailed this card to her aunt in Port Huron, letting her know she'd be coming up for a visit the following week and promising to fill in "Uncle Bonnie" on some unfinished business.

• Caption: "General Motors Building, Laboratory and Convention Hall, Detroit, Mich."
• Card no.: 1800
• Postmark: Detroit, Mich., Apr 1930 (date partially obscured)
• Status: Posted