County was demarked from Fannin County on April 3, 1846, and named for Collin
McKinney, one of the first settlers of the county and a signer of the Texas
Declaration of Independence. The original county seat was Buckner. Because
this town Buckner was not within three miles of the center of the county,
however, McKinney became the county seat in 1848. Like the county, McKinney
was named for Collin McKinney.
settlement of Collin County can be divided into two phases. The first occurred
during the early period of the county's history, from 1840 to 1860. The second
phase took place during and after the arrival of railroads. The settlements
established before the construction of rail lines seldom survived if the
railroads bypassed them.
influence of James W. Throckmorton, a native of McKinney and Texas state
senator, resulted in Collin County's vote against secession, 948 to 405, in
1861. Once Texas joined the Confederacy, however, more than 1,500 residents of
the county enlisted in the defense of the South, led by Throckmorton, who rose
to the rank of brigadier general.