Sargent was born on July 5, 1863, on the Rancho Potrero de San Carlos in Carmel Valley, California.

He spent his formative years on the ranch, comprising 24,000 acres (9,700 ha) owned by his father, Senator Bradley Varnum Sargent.

Sargent received his early education in the public schools of Monterey County and in 1891 attended Santa Clara College, graduating in 1884 with a Bachelor of Science (B.S.)

Sargent served as the grand vice chancellor of the Knights of Pythias and is also affiliated with the Benevolent and Protective Order of Elks, Native Sons of the Golden West, Fraternal Brotherhood, and other organizations.

[1] Upon returning to California, Sargent joined the office of E. B. Stonehill, the district attorney of San Francisco and took part in the presidential election of 1888.

[7] He played a key role in shaping the law governing juvenile cases, which mandated the appointment of a probation officer under the direct supervision of superior court judges.