Why should we think of Hymen Lipman on March 30?
[I]t is Hymen Lipman of Philadelphia who has the idea of attaching a piece of rubber inside one end of the pencil. On this day in 1858, Lipman is issued a patent for marrying the pencil to the eraser.(via Boing Boing)
Unfortunately for Lipman, the patent would later be revoked, when the U.S. Supreme Court rules in 1875 that a pencil with an eraser is just a pencil with an eraser and not a new invention.
Hymen L. Lipman makes his mark in pencil history (Smithsonian Magazine)