Built for the Oates family in six months during the rainy winter of 1904-1905, the 1905 Comstock House was designed by local architect Brainerd Jones, who also created most of the buildings in Petaluma's historic core as well as nearby Belvedere. Jones gave the house whimsical features, including asymmetrical left and right front sides, an off-center gable with an incomplete right side, and a porch with a decorative giant bracket that appears to support the upper floors. Nellie Comstock bought the house for $10,000 in 1916, and members of her family lived there for the next 74 years. It was the residence of Judge Hilliard Comstock, a civic leader who directed the expansion of the school system, the creation of Howarth Park, and the drive to build Memorial Hospital. The Oates and Comstock families also had notable roles on opposite sides of the Civil War: Nellie's father headed the abolitionist group that funded John Brown's armed effort against slavery, while Mr. Oates' brother led the Confederate troops at Gettysburg that lost the Battle of Little Round Top, which some scholars believe was pivotal in the South's defeat.