With more than 350,000 objects and seven million books and documents, this is among the world's largest collections of Americana. Highlights include one of two surviving Revolutionary War officer's uniforms, photographs from the Civil Rights movement in Baltimore, and Francis Scott Key's original manuscript of 'The Star-Spangled Banner' (displayed at the top of the hour). The 10ft-tall replica mastodon – the original was preserved by artist and Maryland native Charles Wilson Peale – is impressive. A few original bones are displayed.

　　There are often excellent temporary exhibits that explore the role of Baltimore residents in historic events.