what county is mckinney tx in
McKinney is a city in and the county seat of Collin County, Texas, United States, and the second in population to Plano.As of the 2010 census, the city's population was 131,117, making it the 19th-most populous city in Texas.or the first 125 years of its history, McKinney served as the principal commercial center for the county. The county seat provided farmers with flour, corn, and cotton mills, cotton gins, a cotton compress, and a cottonseed oil mill, as well as banks, churches, schools, newspapers, and from the 1880s, an opera house.