Yeah but the reality was the US had too much money tied up with the Entente and little to gain from German victory. If you want to have the US angry enough to actually join Germany and engage in a long bitter struggle that brings the war right to Americas doorstep, you need more than a few mistakes by the British. Wilson (unlike the Kaiser) just can't unilaterally declare war himself, he needed congressional support and that's going to be a hard sell. You need to poison relations earlier between Britain and America somehow, they aren't going to reverse a whole lot of policy on a whim for a few ships being sunk.
Have some ignorant RN captain (There are enough of them in 1914 before war wises them up.) do this... Trent Affair - HISTORY. That will start an event chain.