Mercer's Colony Eastern Boundary. In 1844 Charles Fenton Mercer led an effort to colonize an area in north central Texas equal to portions of 18 current Texas counties. His contract to settle 500 families in five years was complicated by various legal issues, but land certificates were ultimately issued to the settlers. Mercer severed all connections with the grant in 1852. This marks the east line of the colony whose boundaries were approximately Palestine and Waco on the south, the Brazos River on the west, and the McKinney area on the north. Descendants of Mercer's colony settlers still reside in Texas. (1997) Incise on base: Researched by Nelda Jones #11428