The name "Old Three Hundred" refers to the settlers who received land grants in Stephen F. Austin's first colony in Mexico.  Although not originally enthusiastic about the project, Austin continued the colonization activities after the death of his father, Moses Austin.  He traveled to San Antonio, where he met with the Spanish governor Antonio María Martínez. The governor acknowledged Stephen F. Austin as his father's successor, allowing the colonization activities to proceed.

Austin agreed with Martínez to be responsible for all administrative tasks after he arranged for settlers to come to Texas in exchange for land; in payment for his services, Austin would collect 12½ cents an acre in compensation. Austin returned to New Orleans and sought willing colonists and by the end of the summer of 1824 most of the Old Three Hundred were settled in Texas.