Hugh Mordicai Fuller was born in Monroe County, Mississippi in 1832. He was named for his two grandfathers: Hugh Randolph and Mordicai Fuller. Hugh Mordicai Fuller was educated in Franklin County, Alabama. In 1853, at the age of 21, he rode by horseback to Sherman, Texas where he soon acquired a large parcel of land six miles southwest of the town of Sherman. His brother, David W. Fuller, born 1835 in Monroe Co. Mississippi, also moved to this area.

The General Index of Deeds, Vol. 30, No. 109 (Deed Book Q, pp. 14) shows that on 1862, Hugh M. Fuller was granted, by letter patent, 160 acres of land on Choctaw Bayou in Grayson County, about 5 1/2 miles southeast of Sherman. This grant, by Gov. Lubbock, was "by virtue of preemption certificate No. 34 issued to Hugh M. Fuller by the Chief Justice of Grayson County on the 4th October 1850." Family history says he arrived in 1853, this deed implies at least 1850.

Hugh M. Fuller married Martha Ann Savage, daughter of Hiram and Mary A. (Williams) Savage of Grayson County, on 1 Feb. 1855. Hiram Savage had bought land on Choctaw Bayou in January 1855. He built one of the first cotton gins. He was a Mason and a Baptist.

Hugh M. Fuller served in the Civil War, as a private in Company B of Martin's Regiment, 5th Partisan Rangers, Texas Cavalry. His service record is shown on the Texas Confederate Records (microfilm) Roll #202. This muster record shows he mustered-in on 5 July 1862 at Sherman, Texas, where he was placed in Captain John Randolph's Company, 1st Battalion, Texas Partisan Rangers, of Martin's Cavalry Regiment. The muster roll also shows he rode 15 miles to rendezvous for this mustering-in, on a horse valued at $100 and with $30 worth of equipment.