Earlier this month, Michael “Mike” Bloomberg announced that he’s donating $600 million to four historically Black medical schools. This caught my attention. I researched Mike and his media and technology company. I’ve been reading biographies about media entrepreneurs recently, so I read the updated version of his autobiography Bloomberg by Bloomberg.

Mike was born in 1942 in a middle-class family. His father was an accountant at a dairy. His hometown, Medford, Massachusetts, was a blue-collar city outside Boston where few people attended college. Mike attending Johns Hopkins was serendipitous—someone at his part-time job told him about Hopkins and encouraged him to apply. He was an average student but got into Harvard Business School, likely because of his various leadership roles as an undergrad.

Mike planned to serve in the military to fight in the Vietnam War after graduating from Harvard, but the military rejected him because of his flat feet. Jobless and with student loans to pay a few weeks before graduation, Mike took the advice of a friend who suggested he apply to be an institutional salesperson or equity trader. Mike had no idea what people in those roles did, but he needed money. He was hired at Salomon Brothers in 1966. Securities trading and sales were considered second-class jobs, not something Ivy League graduates did. The job didn’t pay even enough to cover his bills. He started off doing clerical work but eventually got a break—he was asked to help build the firm’s business doing block trades, a new thing at the time, for institutional clients.

Block trading became Salomon’s most visible department, and Mike was promoted to general partner in 1972. In 1973, his boss had a fistfight with another partner on the trading floor, and Mike was given responsibility for all stock trading. In 1979, the block-trading business became unprofitable, and Mike was assigned to oversee the firm’s information systems.

Mike pushed for Salomon to implement a computer system that would enable cooperation across departments and firmwide risk management. This push caused a political battle between Mike and some members of the firm’s executive committee. Then in August 1981, the executive committee merged the 71-year-old partnership with public commodities trading firm Phibro Corporation. The merger was bittersweet for Mike. His ownership in the partnership netted him $10 million in cash and convertible bonds when the merger closed. But his rivalry with certain executive committee members had caught up with him; he wasn’t offered employment with the merged company. He was being fired.

After fifteen years, Mike was leaving the only full-time job he’d ever known. He was 39 and had a wife and young daughter. He had to figure out what he was going to do next.