Trying to identify trees at Peeble Island

I went to Peebles Island to practice tree identification.  I took several pictures of each of the trees I was working on.  Here are four pictures of the first tree:

A few of the leaves were lobed, but most were not.  Because of the mix of lobed and unlobed on the same tree, I thought it might be mulberry.

Here are three pictures of the second tree:

I could not figure it out from the many books that I had, but Bob said he thought it was hackberry.