It could Ulmus glabra. The leaf margins are double serrate and the shape fits better than other Elms except for maybe Ulmus laevis.
http://www.tree-guide.com/wych...
http://www.tree-guide.com/elm-...
Location of U. glabra .. which is only a rough guide.
http://michiganflora.net/speci...
Ulmus laevis leaves are very similar with maybe a more ovate shape.
http://www.tree-guide.com/euro...
Ulmus laevis isn't featured on the site .. and the others, at a glance, don't match so it looks like Ulmus glabra is more probable. The other species should be checked out to be sure.
http://michiganflora.net/genus...
I can't find a tree of U. glabra which has immature bark, but the more mature bark on the following link does show raised horizontal bumps (lenticels). The same can be seen on the tree-guide link.
http://www.bomengids.nl/uk/soo...
Young twigs ..
http://www.british-wild-flower...
