Last night I watched a very interesting documentary by Gary Hustwit called Helvetica. It was a fascinating conversation with graphic designers about the font Helvetica, typography and graphic design. Helvetica was created in 1957 by Max Miedinger and Eduard Hoffmann at the Haas type foundry in Munchenstein, Switzerland and within a decade became the world's most successful and well-known font.
The story reminded me that the first U.S. design patent, issued in November 1842, was for a type font. Unfortunately, the surviving copy is a handwritten document that does not include drawings of the font. (See D1.)
The inventor (or designer) was George Bruce, a Scottish immigrant and owner of a type foundry in New York. Bruce was one of the most successful type designers in the 19th century. His inventions included numerous fonts and improvements to type-casting machines.
Since 1842 there have been thousands of design patents for fonts. Fonts are classified in the USPC under Class D18, Printing and Office Machinery, subclasses D18/24-D18/33. It's interesting to note that Bruce's first patented font is still being cited in recent design patents.