From the Sanger city web site:
Sanger! Whence the name? Fortunate, indeed is the city with a name of which it may be rightfully proud and the history of which is definitely known.
For years "who named Sanger?" Has been a much discussed topic locally and the answers have always been somewhat evasive and never based on anything authentic. The most popular of these rumors was that a member of the original town survey party was named Sanger and that the town was named for him about 1887. At various times local people would attempt to ascertain the facts concerning the naming of the town but always to no avail until the Golden Jubilee Edition was planned.
Files and histories were scanned, old timers were interviewed, and still the origin of the name was a mystery until finally the post office department in Washington was consulted.
The identification of the name "Sanger" was not difficult, for prominent in the minds of the members of that department was the name of Miss Alice B. Sanger, known as the "Betsy Ross of the post office department."
The letter seeking the information was referred to Miss Sanger who had retired only recently after 40 years' service in that division and through her the history of the naming of the town was found.
In 1887, Miss Sanger's father, Joseph Sanger Jr., then secretary and treasurer of the Railroad Yardmasters Association, attended its annual convention in San Francisco and it was at that meeting that a group of railroad officials informed him that they had named a town in Fresno County for him. At that time the town was being surveyed.
Joseph Sanger never saw the little spot in Fresno County named in his honor by his railroad friends; presumably officials of the Southern Pacific line. Neither has his only daughter, Alice B. Sanger, who was extended an invitation by the Sanger Chamber of Commerce to attend the Golden Jubilee celebration. However, Miss Sanger has stated that she plans to visit the town bearing her family name soon. She writes that friends of hers, who have toured the west have returned to her glowing accounts of the little city in Fresno County, California, bearing her name.
Joseph Sanger Jr., and his father were both born in Watertown, Mass. of English parentage. Sanger's mother who was also born in Watertown of the English line, died when only 20 years old, and Sanger was reared by a stepmother. Sanger was a person of strong character; of retiring disposition, and high minded to an extreme, but with many staunch friends. As a young man, he took a great interest in Masonry and became a past master of the Pequosette Lodge before moving his family to Indiana where his lodge work and his career ware both cut short by illness. Before moving to Indiana he was associated with his father in the contracting and building business, having built the town hall and several churches in that city.
Sanger was married to Susan Webster Smith of Compton, N.H., and her sister Harriett, was the wife of Hiram M. Britton, master mechanic of several railroads and later general manager of a branch of the New York Central lines. Since the two men had been boyhood chums, it was through Britton's influence that Sanger moved to Indiana to begin railroading. Due to illness his railroad career was short lived and he was an invalid for 15 years preceding his death in 1899. Mrs. Sanger passed away in 1924 and both were buried at the New England home. However, the couple spent several years with their only daughter, Miss Alice B. Sanger, after she went to Washington in 1889 to become the first woman clerk in the White House.