The leaves are heart-shaped, with a pointy tip.
I took four photos to try to capture the buds, but mostly they came out fuzzy. The buds were red. In the first photo of a bud, you can also get another look at the shape of the leaves.
The bark seemed thin, and had both vertical and horizontal lines.
I don't have a photo of the fruit, and there was little fruit, but in one place I did see balls on a stalk.
I saw the red buds, and recalled that there is a type of tree called the redbud. I looked for redbud photos on the internet. Most of the photos showed spring flowers, but from what I could find of leaves and bark, the leaf shape seemed to match, but the redbud bark seemed thicker. Also, redbud trees seemed to be shorter than the tree I observed.
Next I went through What Tree is That? It's always hard to work with that book, but the best I could tell was that the tree I saw is linden or basswood.
When I looked through the leaf pictures in The Tree Identification Book, I saw that the tree I observed did not match the redbud leaf, because the redbud leaf is not toothed. The leaf that seemed to match was American linden. I then turned to the American linden page of the book. On that page, I found that in addition to the leaf matching, the buds and the fruit also match.
I checked Trees of New York and The Sibley Guide to Trees. They did not really offer any new insights, but they seemed to agree that this tree is American linden, also known as American basswood, also known as basswood.
One thing that concerns me it that the bark shown in the tree books does not particularly match the bark on the tree that I saw. I looked on the internet for pictures of linden bark. Most did not match the tree I saw, but this one did look similar.
