Here are 25 unheralded Black pioneers and trailblazers you should know. And a big part of what made the company so successful is thanks to Mark Dean, an engineer whose work helped create the company's ISA bus. WALKERCraig Barritt, Getty Images for EssenceKnown as \"the first Black woman millionaire in America,\" Madam C.J. Estimates put the number of employees somewhere around 40,000 at a time when holding a job as a Black woman wasn't necessarily common. An educator from Brooklyn, Chisholm became the first African-American woman to serve on the United States Congress, remaining in office from 1969 to 1983.