My impression was that in the US, any surname can be used as a first name. Wasn't there even someone with Mackenzie as first name? Plenty of Harrisons, Taylors

My impression was that in the US, any surname can be used as a first name. Wasn't there even someone with Mackenzie as first name? Plenty of Harrisons, Taylors and other names that really don't sound like a first name.