Originally built by Marshall Field & Company to replace and expand H.H. Richardson's Marshall Field Wholesale Store, the Merchandise Mart was the largest floor area in the world until the Pentagon was built in Washington, DC. Joseph P. Kennedy, Sr., purchased the building in 1945 for $12 million. There are 2,000 additional owner-controlled parking spaces in adjacent buildings, in addition to the 250 covered spaces in the building itself. First and second floors contain numerous amenities, including 22 quick service restaurants, a 420-seat food hall, Marshall’s Landing 12,000-square-foot lounge/restaurant connected to a 50-foot-wide Grand Stair leading to the building lobby, an on-site CTA stop servicing the Purple and Brown lines, and a US Post Office. In addition, the MART contains a full-service 20,000-square-foot fitness center, a new conference center with capacity for 225 people, and a 10,000-square-foot River Deck for outdoor green space along the riverfront. In 2018, this building was awarded the Fitwel Certification, which is the leading global health certification that optimizes buildings to support occupant health. The MART has LEED Gold certification.