General Mariano Vallejo was the founder of Sonoma, California, but his tombstone at Mountain Cemetery in Sonoma gives the wrong date of birth—July 7, 1808.
There's even documentation to back it up. A letter written by a genealogist at the Monterey Diocese says Vallejo was born on July 4th, 1807, the day before his baptism. But trying to correct history hasn't been easy. The cemetery is maintained by the city of Sonoma.
The people here at city hall say they'd be happy to change the tombstone, but it's not up to them. They say only family members can make that call. [Link]