Ambrose is on Farm Road 1897 six miles southeast of Denison in the far northeastern corner of Grayson County. It is near the site of Old Warren, which is just across the Fannin county line. Ambrose was named after Ambrose Bible, who came to Texas from eastern Tennessee in 1883. He bought land from S. E. Elliott out of the Daniel Montague survey dated February 20, 1845, and settled in the old Fannin County, out of which Grayson County was formed in 1846. The Denison, Bonham and New Orleans Railway Company bought right-of-way from J. P. N. Haun and Ambrose Bible on March 3, 1887, to run a spur from the Missouri, Kansas and Texas Railroad in Denison. The company's first attempt failed.
On January 10, 1902, land was surveyed, laid out, and mapped for Ambrose, and in September a post office opened with James B. Moore as postmaster. On July 28, 1903, Bible deeded the land for the right-of-way and the station grounds to the original railway company. He donated an entire block for the school, which was built in 1907. The town had three churches—Methodist, Church of Christ, and Baptist. Dr. Frank Miller was the first doctor. Oscar Sanford owned the hardware store, C. D. Jordan the drugstore, and Calmy Brown the bank. The town had a restaurant, a general store, and a blacksmith shop. The farmers shipped cotton, watermelons, sand, and gravel. In 1917 a new school building was erected. In 1919 the town reached its zenith. The population never rose above sixty because the majority of people lived on farms. By 1927 the DB&NO railroad had failed. The post office was moved to Bells in 1930 and served Ambrose on a rural route. In 1940 the school was consolidated with that of Bells. The census in 1980 reported a population of forty-one and no businesses in Ambrose. The school building was being used as a community center. The population was still forty-one in 1990. In 2000 the population grew to ninety. In 2014 the population was unchanged.