The president, at that date, was John F. Kennedy.
According to Cornwallis he would have: (1) either endeavored to escape to New-York or (2) would
notwithstanding the disparity of numbers have attacked them in the open
field. This was what he said in a letter he reported to Sir Henry Clinton when he failed to defend the York and Gloucester posts.
Most Americans supported isolationism. They didn't want to engage in another European war. Although this agreement didn't include sending troops to Europe, it involved sending 50 destroyers to UK, so the amount of help was rather major.
