In 1927, McCormack sold his interest in U.S. Trucking and entered the sand and gravel business by obtaining an interest in United Sand and Gravel, a company owned by former Assistant District Attorney Edward J. Chapman and McCormack's cousin and close friend Bronx politician Robert L. Moran. United Sand and Gravel became Transit-Mix, which, as one of only two concrete plants located within the city, provided millions of cubic feet of concrete for public and private construction projects including the Empire State Building, Chrystler Building, United Nations, Radio City, Waldorf-Astoria, New York Central Building, Guggenheim Museum, Lincoln Center, 1964 World's Fair Grounds in Flushing, Cross Bronx Expressway, Major Deegan Expressway, Long Island Expressway, TWA Flight Center at JFK Airport designed by Eero Saarinen, the Whitestone, Throgs Neck and Verrazano-Narrows bridges and the World Trade Center. After McCormack's death, Transit-Mix was left to McCormack's daughter, who sold the corporation to Edward J. Halloran, owner of the Halloran House Hotel on Lexington Avenue at 49th Street. In 1986 Halloran and Transit-Mix were indicted, along with Anthony Salerno and other members of the Genovese Crime Family, for bid rigging, extortion, gambling and murder conspiracies. Halloran disappeared under mysterious circumstances in 1998 and remains missing to this day.