Entrepreneurial and driven, the younger Kislak got his real estate license while still a high school student at Newark Academy. He earned a degree in economics from the Wharton School of Finance at the University of Pennsylvania, graduating early to serve as a naval aviator in World War II. Upon returning home to New Jersey in 1945, Jay entered the family real estate business full time and made it his life's work.

Kislak and his first wife, Beverly Braverman, had three children—Jonathan, Phil and Paula. Kislak and Braverman remained friendly until her death in 2015. In the early 1950s, he moved his family to Miami, establishing what would become one of the country's largest privately held mortgage banks, originating and servicing loans nationwide for more than 40 years. Until his death, Kislak served as chairman of the Kislak Organization, which today focuses on real estate investment and brokerage.

Through a shared passion for art, Kislak met Jean Ellis Hart and they married in Miami in 1985. They shared adventures that took them from the North Pole to the South Pole, and included every continent.

Jay Kislak aboard the aircraft carrier USS Intrepid in New York Harbor in June 2017, during a 95th birthday party

While building a successful business enterprise, Kislak also created a cultural and historic legacy – unique collections of rare books, maps, manuscripts, paintings, prints and artifacts. With Jean, he established the nonprofit Jay I. Kislak Foundation for the conservation and study of materials related to the cultures and history of the early Americas.

In 2004 he donated more than 4,000 items from the collection to the Library of Congress. This extraordinary gift to the American people, is now on permanent display and features one of his greatest acquisitions – the 1516 Carta Marina Navigatoria, the first printed navigational map of the world by the celebrated German mapmaker Martin Waldseemüller.

Through a landmark gift in 2017, Kislak and his family established two permanent South Florida homes for his internationally significant collection—Kislak Centers at the University of Miami and Miami Dade College Freedom Tower.

The Kislak Family Foundation also established Kislak Centers at the University of Pennsylvania, and at Monmouth University, West Long Branch, NJ, and supports programs at Florida State University Real Estate Center, the University of Florida College of Veterinary Medicine, and other institutions.

Kislak held leadership roles in a long list of local, state and national organizations, including the US Department of State Cultural Property Advisory Committee; the boards of trustees of the National Park Foundation and Eisenhower Fellowships program, Mortgage Bankers Association of America, Greater Miami Jewish Federation, Jewish Family Services, and United Way, among others.

The King of Spain, Juan Carlos I, granted Kislak the prestigious Encomienda of the Order of Merit Civil, and he was named a “Miami Living Legend” by Miami Today newspaper, a national Unsung Hero by Curtiss Mansion, and received the Lifetime Achievement Award from the Association of Fundraising Professionals on National Philanthropy Day 2017.

In addition to Jean Kislak, his wife of 33 years, Kislak is survived by his children, Jonathan (Tina) Kislak, Philip (Silvia Figueroa) Kislak, and Dr. Paula (Dr. Peter Mangravite) Kislak; step-daughter Jennifer (Noel) Rettig; grandchildren, Rebecca, Jason, Tamara, Libby and Jane; and great-grandchildren, Ezra, Simon, Kayla, Julia, Stokes and Aura. He is also survived by his brother, David, and many nieces and nephews.

Kislak's family was among the 25 founding families of Temple Beth Am, now one of the largest temples in Florida, and he also was a member of Temple Israel of Greater Miami, and Synagogue Adas Yoshurun in Rockland, ME. A celebration of life will be held Sunday, October 7, 2018, at 4 p.m., at Temple Beth Am, 5950 North Kendall Drive, Pinecrest, FL.