The 1900 Census shows him as married to Marie Fountain born in Ohio in January of 1855. It says they have been married for 39 years (not likely since that would mean she was married at age 6!) and that she is the mother of one child.4461

An Illustrated History of Sacramento County, California4442
by Hon. Win. J. Davis
Chicago: The Lewis Publishing Company 1890.
California State Library #131744
Page 796

William Andrew Fountain , elder brother of James B. Fountain, and senior member of the business firm of Fountain Brothers, a brick-makers, is the oldest living son of Joshua Fountain, a native of the state of Delaware, born near Milford in 1811, and Prudence Rebecca (Walton) Fountain, who emigrated to Beard's Prairie, Michigan, in 1835, where the subject of this biography was born March of the following year (1836). As stated elsewhere in this volume, the family soon removed to Van Buren County, Iowa, where grandfather Andrew Fountain, who was a farmer, died in 1844. In the spring of 1850, our subject, at that time just twenty-four years of age, his father, his uncle Lloyd Rollins, a daughter of the latter, and three young men, made up a party to cross the plains overland to the "land of golden promise." They left home on the 9th of April, crossed the Missouri River at Council Bluffs on the 29th, the north side of the Platte, and via Fort Hall, arrived safely at Grass Valley on the 15th of September following. They wintered there, and in the spring of 1851 started for Gold Lake mining district. Abandoning that project they mined on the Feather River during that summer, at Bidwell's Bar and at Oregon Gulch until November, 1852, when our subject came to Sacramento and worked for his father, who had started a brickyard on Eighth and O streets. (For full particulars of locations, which were changed from time to time to accommodate the advancing requirements of a growing city, see sketch of Joshua Fountain, the pioneer brick-maker.) In 1859 Mr. Fountain started business on his own account, taking a contract to make brick for the wine-cellar, residence and other buildings for Mr. Bell, at Gold Hill, Placer County, and in 1862 and 1863 had a contract for constructing a portion of the levee near Freeport. In 1863 and 1864 he burned a kiln of brick at Auburn, and also made the brick for the courthouse and jail at Woodland that year. In 1865 and 1866 he bought a farm lying between Elk Grove and Georgetown, and was engaged in farming for two years, but in the meantime he burned a kiln of brick at Elk Grove. In 1867 the present firm was established. (For full particulars see sketch of J.B. Fountain.) Mr. Fountain has always taken an active interest in the local politics since the organization of the Republican party, to which he belongs, but has never been willing to accept any official position. He is a member of the Sixth Street Methodist Episcopal Church, and he has had his residence on the corner of Fifteenth and P Streets for twenty-three years. In 1877 he was associated with Hon. John Q. Brown in street contracting, cobbling and graveling the principal streets, and they continued the business for several years. The latter gentleman was afterward mayor of the city for six years, and is now president of the San Francisco Board of Trade. July 28, 1859, Mr. Fountain was married to Miss Abbie Louise Brewster, a native of Massachusetts, the daughter of Mr. Charles Brewster, a florist. She was a devoted Christian woman. Her death occurred September 13, 1879. The family consists of six daughters, viz: Henrietta, now Mrs. Charles Lowell; Clara, now Mrs. Charles Hockell; Grace; Anne; Lizzie; and Abbie. In 1881 he was again united in marriage to Miss Helen Powers, an earnest Christian woman, a native of New York State. Her death occurred April 23, 1888. Of their private affairs, the home life, of the tender interests which cluster around the family altar, it is not our province to speak, but we must be permitted to say that the influence of such homes are far-reaching; the influence of such lives will ever remain a monument to enduring memory. [From the 1901 Sacramento City Directory: Page 222 Fountain, Wm. A. brick mfr. r.1430 P]