Since the McKinneys never lived in McKinney, I don't think they "founded" McKinney, Collin Co. Texas.
Collin and Daniel McKinney (with sister and mother)moved to an area six miles east of the present city of Texarkana.Theyarrived there September 15, 1824.
In 1831, the McKinneysmoved farther west and settled on Hickman's Prairie on the Red River, which was then in Miller County, Arkansas, but is now in Bowie County, Texas.
Sometime prior to 1846, he moved his family to a point near the line of present day Collin and Grayson counties.Collin died on September 8, 1861, at the age of ninety-five.He is buried cemetery at Van Alstyne, Texas.
Since Collin McKinney was a signer of and one of the five who drafted the Texas Declaration of Independence, when a new county was created from Fannin County in 1846, it was named Collin in his honor.When the county seat was moved from Buckner to a point near the geographical center of the county in 1848, he was still further honored through the naming of the county seat, McKinney.