Help Identifying this Elm

[Time Wizard]

A few years ago I noticed two seedlings growing in my backyard, so I threw them in some pots and started growing them out. One of them (pictured) is currently in the ground. There are a handful of big, corky elms in my town that I believe are American elms. I'm guessing some seeds from one of these made their way into my yard. The leaves are doubly serrated and at least somewhat asymmetrical at the base. The trunks are smooth unlike the elms in my neighborhood, but the two I have are only about three years old from seed.

Are these American elms or something else?