Miles: Sorry, I'm busy at the moment what are the three classes of prescription drugs A graduate of St. John’s University in Queens, N.Y., Slattery worked for the Sheraton Hotel corporation beginning in the 1970s. While working at a hotel in Queens, Slattery became close to his boss’s son, Morris Horn. The two joined forces with other investors to start a property management company, buying up older hotels across New York City.