Cynthia Ann Parker was born to Silas M. Parker and Lucy Duty Parker in Crawford County, Illinois. Considerable dispute exists about her age, as according to the 1870 census of Anderson County, Texas, she would have been born between June 2, 1824, and May 31, 1825. Because of the Americans' war-fighting ability against the Indians, the Mexican government had originally encouraged Americans to establish frontier settlements to block the continuing raids of the Comanche deep into Mexico. Consequently, the Parker clan, which had a long history of frontier settlement and fighting, was encouraged to settle in Texas. When Cynthia was nine years old, her family and extended kin moved to Central Texas and built Fort Parker, a log fort, on the headwaters of the Navasota River in what is now Limestone County. Her grandfather, Elder John Parker, the patriarch of the family, had negotiated treaties with the local Indians who were subject to the Comanches, and historians conjecture that he believed those treaties would bind all Indians and that his family was safe from attack.