I have nothing against the Brits. I admit it. I'm an Anglophile. The Battle of Britain actually began on July 10, 1940, and lasted until September when it gradually fell off. Were there Americans in the Battle of Britain? Yes, there were. At the end of the movie, and I doubt I'm giving away any spoilers here, there's a casualty list of the countries involved. The British Commonwealth bore the brunt of the casualties. The United States and Israel didn't take it all on the chin the way the Brits, Canadians, Aussies, and Kiwis did, but we definitely took it on the chin. Technically, in 1940, the United States was neutral. Americans who joined the RAF, or RCAF, like my father did, lost their citizenship. Our neutrality laws were that strict. The Americans in the RAF became part of the legendary Eagle Squadrons whose exploits are so underrated. They're the unsung heroes of World II. Their service in the RAF was from September 1941 to September 1942. The American contribution to the Battle of Britain can't be dismissed. It should be the subject of its own movie.
Review of Battle of Britain
