The U.S. is a first-to-file country. More info on first-to-file here:
First to file and first to invent - Wikipedia
That said, many/most patents have holes in them that competitors can fill through their own patents. (Speaking purely as a non-attorney).
First to file and first to invent - Wikipedia
That said, many/most patents have holes in them that competitors can fill through their own patents. (Speaking purely as a non-attorney).