The next year he settled in Stephen F. Austin's Colony, claiming a headright to Texas land while continuing his trading activities.

[1] She moved to San Felipe de Austin that year while McKinney continued dispatching loads of cotton overland and by water.

[2] McKinney started a mercantile partnership with Samuel May Williams perhaps as early as 1833, acquiring the warehouse of Walter C. White in Brazoria.

McKinney was the managing partner of the mercantile business in the spring of 1834 while Williams was still engaged in San Felipe de Austin.

[3] The partnership formalized as McKinney and Williams operated as commission merchants: they advanced notes or supplies to farmers in exchange for future cotton produce.

Starting by moving goods over Texas rivers by flatboard, by 1835, they had acquired three steamships and ran packets between their warehouse at Quintana and New Orleans.

McKinney invested in Houston outside of the partnership, accumulating city lots and buying a minority share in the Allen brothers' Texas capitol building project.

Mayor John M. Allen, a career soldier, absconded with the municipal archives and stored them at his residence, which he guarded with two cannons.

That committee's investigations of the state's accounts concluded that the Texas auditor, the comptroller, and the attorney all failed to report under-reporting revenue by private companies.

[14] In 1850, McKinney established a ranch on 40,000 acres (16,000 ha) in Travis County that he purchased from Michel Branamour Menard, originally part of the Santiago Del Valle Land Grant, in 1839.

The Confederate government appointed him as a cotton agent, and he incurred personal debts while performing this duty, leaving him with an estate diminished to $5,000.

Several artifacts from his homestead remain on the park grounds: the ruins of his masonry house, stone walls, a cabin, and a mill.