Obed Harvey was born September 7, 1825, in Sodus, Wayne County, New York. As was customary at the time, he began his medical studies in apprenticeship with Dr. George W. Richards in St. Charles, Illinois. He attended lectures in La Porte [Indiana?] and at Rush Medical College in Chicago. He took his degree in 1849 from Rock Island Medical College, and practiced medicine for a short time in Genoa and Elgin, Illinois. In August of 1850 he came to Placerville, California, having begun the overland journey in late 1849. In Placerville, he formed a partnership with Dr. Asa Clark and with him conducted the County Hospital; the two were the leading physicians of El Dorado County.

During a later partnership with Dr. Benjamin F. Keene, Dr. Harvey became interested in political life. He was the delegate from El Dorado County at the state medical society's first convention in 1856, and helped elect Dr. Keene the first president of the society. In 1857 Dr. Harvey was made vice-president of this organization. Dr. Harvey represented California at the May, 1858 convention of the American Medical Association. He left for the East in August of 1857, sailing by steamer from San Francisco to Panama, crossing the Isthmus, and boarding another steamer, the Central America , for the trip to the eastern seaboard. The ship's surgeon having been taken ill on the first day out of Havana, Dr. Harvey was acting surgeon when theCentral America was wrecked in a gale off Cape Hatteras on September 12, 1857. Dr. Harvey was rescued after floating on a piece of the wreck for nine hours. His celebrated letter from New York, which appeared in the Sacramento Union in October of 1857, described the wreck and the medical and surgical aid given to the passengers. This adventure, plus his able representation in Washington at the AMA convention (the first time California was represented), ensured Dr. Harvey's increased prominence upon his return to California in 1858.

Over the next few years, he continued to serve on various committees for the state medical society, as well as on committees of the AMA and as a delegate from El Dorado county at the state's first railroad convention. During the Civil War years, Dr. Harvey --a staunch Union Democrat --was elected state senator from El Dorado county, and also as acting surgeon for the 4th Regiment, California Volunteers. In 1864 he went to Washington "in the interest of the co-tenants of the Chabolla Grant," the large parcel of land he'd obtained in 1852 that was part of the old Rancho San Juan de los Moquelumnes tract (patents for same giving him clear title were obtained in May of 1865). During this same trip Dr. Harvey also visited some of the Army hospitals in Virginia; the current collection includes some of the official documents allowing him to pass into the war zone where these hospitals were located. In 1869 he laid out the town of Galt on the land he'd acquired in 1852 and on which he'd made school land surveys in 1853. He was largely instrumental in carrying through the South Fork Canal, described as "the life of El Dorado county," and also assisted in constructing the Pacific Quartz mill, just east of Placerville. In 1871-1872 he was a member of the State Assembly, after which he became director of the State Hospital (state asylum for the insane) in Stockton; he held this position until his death on January 17, 1894.