Possibly another son two years older than William Andrew since the 1850 census4446 shows an 18 year old Fountain (looks like the name was George Hosa Fountain) living with Joshua and William.

An Illustrated History of Sacramento County, California4442
by Hon. Win. J. Davis
Chicago: The Lewis Publishing Company 1890.
California State Library #131744
Page 670

Joshua Fountain was born in Maryland, February 27, 1811, his parents being Andrew and Rebecca (Barwick) Fountain. His maternal grandparents were James and Mary (Fisher) Barwick. Grandmother Barwick lived to be over seventy. The Barwicks are Marylanders for several generations. His grandfather Fountain bore the name of Andrew, and lived to be nearly seventy. Joshua Fountain's great-grandfather, who is believed to have been also named Andrew, was one of the three brothers, who had come to America from France before the middle of the last century. One settled in Maryland, one in Long Island, and the third went South, but afterward returned to France, where he died leaving, it is said, a large fortune, to his indirect heirs in America. A grand-uncle was a Colonel Fountain in the French-Indian Wars, about 1760, serving on the side of the British colonies; and is said to have received the grant of one or two sections of land over which the city of Baltimore has since spread. Whether the alleged $8,000,000 of Fountain's inheritance includes this as well as the foreign claim, or whether one is confounded with the other, or whether either is genuine, Mr. Joshua Fountain is unable to say, and meanwhile is little concerned about the prospective millions which perhaps is little better than a lawyer's lure to gather a handsome retainer from American Fountains. Joshua Fountain was brought up on a Maryland farm near the Delaware line; and was married in 1834 to Miss Prudence Rebecca, a daughter of Solomon and Anvibator Fountain, born June 15, 1815. He rented a farm for the first year after his marriage, and in 1835 moved to Michigan, where he bought a farm in Cass County. In 1838 he moved to Iowa, buying a farm near Farmington; and then he moved into Lee County, where he farmed for seven years. In 1850, he came to California, across the plains, accompanied by his oldest son, then a boy of fourteen. Arriving in Grass Valley on September 15, 1850, he went to mining there that winter, assisted by his boy. In the spring he went to prospecting for three months, and again settled down to work at Big Rich Bar, on the north fork of the Feather River. Coming down to Oregon Gulch, below Orville, he there mined in the winter of 1851 and the spring of 1852. In the summer he came down to Sacramento seeking a location, having accumulated about $3,000, and bought a place at Eighth and O Streets. The son followed in November with $1,000 which he had won from the mines at the age of sixteen. He went into his old business of brickmaking, which he carried on from 1852 to 1861 in Sacramento. August 20, 1855, Mr. Fountain returned to Iowa to bring out his wife and family of four children, leaving his son in charge of the business and twenty men. In 1857 he bought the ranch of 240 acres in the northeast corner of Franklin Township, which he still owns, and on which he came to reside in 1859. During his brickmaking career in Sacramento he went to Grass Valley in 1857, and there made brick for the Catholic Church of that place; and in 1859 to Suisun City, where he made brick for the courthouse and jail. On his farm he raises grain, though is well adapted for fruit raising with proper irrigation. Mrs. Fountain died December 13, 1871, having borne the following children: William Andrew, born June 9, 1836; James Barwick, July 11, 1838; Ann Eliza, January 13, 1841; George Walton, January 19, 1844; Sarah Jane, December 17, 1847, deceased in 1849; Mary Marion and an unnamed twin sister, who died soon after birth March 17, 1849. Mary Marion died in 1851. Of these, William A. was born in Michigan, and the others in Iowa. The following were born in Sacramento: Joshua Jr, April 2, 1857; an unnamed child, born March 31, 1861, died April 12, 1861; Charles Henry, born April 16, 1862, died February 12, 1884. The two oldest carry on a brick business in Sacramento as Fountain Brothers. Ann Eliza is the wife of F.S. Hotchkiss of the same city. George W. is in the dairy business in the Locke and Levin, son place, below Courtland. He supplies half the stock, the firm the other half and the land, the product being owned in equal shares. He is married to Louisa Hollman. Joshua, Jr. is a traveling salesman for the hardware house of Hillburn brothers of Sacramento, and is married to Clara Hoyt. December 30, 1874, Mr. Fountain was married to Miss Mary Myers, born in Dade County, Missouri, in 1855, a daughter of Garrett Laure, and Delina (Robertson) Myers, the father being of French and the mother of English descent, both now living in Sacramento. 4442

Joshua and Rebecca rented a farm in Maryland the first year they were married. In 1835, they moved to Beard’s Praire, Michigan where their first child was born. In 1838, they moved to Iowa near Farmington, then to Lee County where he farmed. In 1850, Joshua and his eldest son, William Andrew Fountain, joined the wagon train for California. The Fountain party was made up of Joshua, William, his uncle, Lloyd Rollins and three other young men. They left home on April 9, crossed the Missouri River on April 29 and traveled via Fort Hall. They arrived in Grass Valley on September 15, 1850, where they mined through the winter.801

In the Spring, they prospected for three months, then settled to work on the north fork of the Feather River at Bidwell’s Bar. The winter of 1852-53, they looked for gold at Oregon Gulch, below Oroville. By the summer of 1853, Joshua had saved $3,000. He bought a place at Eighth and O Streets in Sacramento. His son, William, joined him that November with $1,000 from his mining. They went into the brick making business which they continued until 1861. Leaving William in charge of the brick business and their 20 employees, Joshua left for Iowa on August 20, 1855 to bring the rest of the family to Sacramento.801