If the activities of founders are limited, then it's possible to spend a significant amount of time in the U.S. as a business visitor but more often than not, a work status/visa is required and the timing of getting that must be managed so that that it's possible to remain and work in the U.S. But it's possible and done all the time. (There's no $100k investment rule by the way unless you are thinking of the E-2 investor visa, which requires a substantial investment and is another type of work visa.)