The Americans resented their mistreatment (taxation without representation) after the French & Indian War, but they had won and weren't involved in a war in 1775. The Russians were reeling from their 1905 loss to the Japanese and they were suffering from WW1 in 1917.
The americans rebelled against King George III, who was depicted as a tyrant, although he wasn't really all that bad. The Russians rebelled against Czr Nicholas II, who was quite a tyrant.
By July 1776 the Americans wanted independence and self-rule; by November 1917 the Russians wanted a worker-run state and self-rule.
American leaders were mostly wealthy landowners and businessmen; Russian leaders were a middle-class lawyer (Lenin), newspaper writer (Trotsky) and a bank-robber/soldier (Stalin).