In 1981, a young and ambitious Donald Trump sat down with federal agents and discussed his calculation in entering the mob-infested world of Atlantic City casinos.
He acknowledged it might tarnish the reputation his family built through traditional real-estate development in New York. He was aware a business partner in the New Jersey beach town knew people who might be unsavory. A Federal Bureau of Investigation agent advised Mr. Trump there were easier ways he could invest, said an FBI memo recounting the discussion.
Mr. Trump went ahead and built an Atlantic City casino, ultimately owning four.
There, as well as in his New York real-estate work, Mr. Trump, now the Republican nominee for president, sometimes dealt with people who had ties to organized crime, a Wall Street Journal examination of his career shows.
They included a man described by law enforcement as an agent of the Philadelphia mob; a gambler convicted of tax fraud and barred from New York racetracks; a union leader found guilty of racketeering; and a real-estate developer convicted in a stock scheme that involved several Mafiosi.