[1] Pendleton was born in Brooklyn in 1859, and attended Brown University, graduating in 1881.

He was admitted to the California bar in 1884 and practiced for a year in San Francisco, where he was also married, before moving to Los Angeles.

He was elected to the California State Assembly from the 74th district in 1892 and served as Speaker in 1901.

He was elected to the California State Senate in 1902, serving for 2 years.

Pendleton was then appointed the U. S. Collector of Customs for the District of Los Angeles in 1906.