Marjorie Merriweather Post, heiress to the Post Cereals business, paid for the house to be built with her husband Edward F. Hutton. She hired Marion Sims Wyeth to design it and Joseph Urban to create interior design and exterior decorations. Post spent US$7 million (equivalent to $109 million in 2021), and it was finished in 1927.
The house has 58 bedrooms, 33 bathrooms, a 29-foot-long (8.8 m) pietra dura marble-top dining table, 12 fireplaces, and three bomb shelters. Mar-a-Lago was declared a National Historic Landmark in 1980.
Donald Trump learned about the estate after unsuccessfully trying to purchase and combine two apartments in Palm Beach for his family. He offered the Post family $15 million for it, but they rejected it. Trump purchased the land between Mar-a-Lago and the ocean from Jack C. Massey, the former owner of KFC, for $2 million, stating he intended to build a home that would block Mar-a-Lago's beach view. The threat caused interest in the property to decline, and Trump ended up getting the property for $7 million in 1985.