Seventeen subspecies of the American Kestrel are recognized, generally based upon plumage, size, and vocalizations.
This is the nominate subspecies Falco sparverius sparverius which is found in most of the United States, Canada, and Mexico.

1st & 2nd photo: Rio Bosque Wetlands Park, El Paso, Texas, USA, 18 January 2019
3rd photo: Aransas National Wildlife Refuge, Texas, USA, 30 October 2006