Nikola Tesla lived to 1943, was a fierce rival of Edison, but his ideas were too far-out and unsuccessful, and he lived in obscurity for the later part of his life. If he had gotten along better...he almost married into one of the wealthy families, and if he had, his career might have been better.
There were blacks involved in science but were relegated to teaching high school. If they had gone to France or other countries, they might have contributed more to the advancement of science.
WW I breaks out in 1854, 1878, 1898 or 1905, leading to more research and advancement in science.