John McMullen,originally from Connecticut,was a carpenter and builder by trade,came to San Francisco in 1876. Within just ten years,he established the San Francisco Bridge Company,just one of several he would go on to establish.This,his Guerrero Street home,built in 1881,was originally a simple Stick Style. While that original designer and builder are unknown,the 1890 alterations and extensions were by famed architect Samual Newsom. As seen 1 February 2023.