Benjamin Ignatius Hayes was born on February 14, 1815 in Baltimore, Maryland. He graduated from St. Mary's College in Baltimore
and was admitted to the Maryland bar in 1839. He married Emily Martha Chauncey in 1848 (died 1857). The Hayes moved to California
in 1850, where he was elected the first Judge of the Southern District of California in 1852 and served as circuit judge for
Los Angeles, San Bernardino, and San Diego. He married Adaleida Serrano in 1866 and lived for many years in the Casa de Carrillo
in Old Town San Diego. He died on August 4, 1877 in Los Angeles, California. His extensive library and scrapbooks were purchased
by Hubert Howe Bancroft, who published the collection as the book, Pioneer Notes from the Diaries of Judge Benjamin Hayes, 1849-1875.