Born in Hagerstown, Maryland, Hall grew up in California. He joined the Army Corps of Engineers as a draftsman in 1865 and was later promoted to Assistant Engineer and tasked with conducting topographical surveys in Oregon and California. In 1870, he prepared a survey of the site for San Francisco’s Golden Gate Park, the beginning of his life-long involvement with the park. He was commissioned to design the park, about which he frequently corresponded with Frederick Law Olmsted, Sr., and subsequently became its first Superintendent. At the same time he operated his own practice. After resigning as Superintendant in 1876 he continued to serve as Consulting Engineer to the Park Commission. Hall became the first State Engineer of California in 1878, developing a seminal state-wide water resource plan during his decade-long tenure. While never implemented, the plan served as a national model. In 1890, Hall again went into private practice as a civil engineer working on irrigation and hydroelectric projects. He continued his involvement in the preservation and promotion of Golden Gate Park until a few years before his death.