After a brief war with Mexico, Texas declared its independence in 1836 and became the Republic of Texas. In 1845, Texas was admitted into the United States. By 1870, the population of Texas was around 800,000. The Bexar District encompassed almost the entire western region of Texas. As the west was settled, smaller counties were formed out of the Bexar District. In 1874, through the efforts of Francis Taylor, Charles Metcalfe and William Kelly, Tom Green County was organized out of the Bexar District. At Francis Taylor’s insistence, the new county was named for Brigadier General Tom Green of the Confederate States of America. General Green died in action at the Red River Campaign during the Civil War.
Ben Ficklin became the first county seat of Tom Green County in 1875 after a hotly contested election between the people of Ben Ficklin and people of San Angela (present day San Angelo). Citizens of each town believed their town more suitable for the county seat. San Angela appeared to have the edge since its population was larger. However, shortly before the election was to take place, the leaders in Ben Ficklin had a judge naturalize several of its Mexican citizens who were then allowed to vote. With its newly naturalized citizens, Ben Ficklin won the election and became the county seat.
Francis Taylor was a co-founder of the town of Ben Ficklin. The town was built on land Taylor inherited from Benjamin Ficklin. Taylor was the first county judge of Tom Green County and is frequently referred to as the Father of Tom Green County. Francis Taylor died in 1879 and is buried at the Ben Ficklin Cemetery.
Originally, Tom Green County encompassed 13 present day counties. The eastern boundary was the present day eastern boundary of Tom Green and Coke counties, and stretched westward to the Pecos River.
As the west continued to be settled, other counties were organized out of Tom Green County. In 1889, Irion County was formed. Immediately to its west present day Regan County was still part of Tom Green County. State law required that counties be contiguous. In order to comply with State law, what is now the panhandle in northwest Tom Green County remained part of Tom Green County (instead of becoming a part of Irion County) to be contiguous with the land west of Irion County. When Reagan County was organized in 1903, the panhandle stayed with Tom Green County.