James Gaven Field was born in Walnut, Culpeper County, Virginia to Judge Lewis Yancy Field and Maria Duncan. After attending a classical school, he engaged in mercantile pursuits at Fairfax, Virginia, and subsequently taught school. On June 20, 1854 he married Frances E. Cowherd until her death in April 1877 and on February 2, 1882 married Elizabeth R. Logwood. In 1848 he accompanied Major Hill, paymaster in the U.S. Army, to California as clerk, and became engaged in the pay department of the U.S. Army. He was chosen a secretary of the convention that framed the first constitution of the state of California in 1850. In October 1850 he returned to Virginia, where he studied law with his uncle, Judge Richard H. Field, and was admitted to the bar in 1852. In 1859 he was appointed as commonwealth attorney for Culpeper county. On April 17, 1861 he resigned as commonwealth attorney and volunteered with Culpeper county's minute men and participated at the Battle of Harpers Ferry. He was promoted to the rank of major on March 23, 1861 and served on the staff of General A. P. Hill. At the Battle of Cold Harbor he was wounded and later lost a leg at the Battle of Cedar Creek on August 9, 1862. He was temporarily out of the army until May 1863 and continued his service until April 9, 1865. Following the Civil War he joined the Conservative Party. He became Attorney General of Virginia in 1877 and in 1879 he argued before the Supreme Court in Ex Parte Virginia that Congress did not have the authority to require blacks on trial juries, but was defeated in the court case and after serving five years in this capacity retired to a farm in Albemarle County, Virginia. During the 1892 presidential election he was nominated as the People's Party vice presidential candidate on the first ballot on July 5 alongside James B. Weaver as the presidential nominee. Field campaigned in the southern and border states and in support of the party's radical reform platform. At a mid-July speech in Gordonsville, in Orange County, he compared the revolutionary impulse of Populism with the AmericanRevolution of 1776 and advised his audience to "Read your Bibles Sunday and the Omaha platform every day in the week." The ticket won five states and received over one million votes. In 1893 he advocated for the impeachment of President Grover Cleveland and later supported William Jennings Bryan in 1896 and 1900. On October 12, 1901 he died in Gordonsville, Virginia.
