Until the abolition of the post in 1922 it served as the official residence in Dublin of the Chief Secretary, the second-in-command (and de facto head) in the Lord Lieutenant of Ireland's administration.

Instead the Chief Secretary's Lodge was rented on a ten-year lease to the United States government, to become a combined ambassador's residence and embassy, on 19 February 1927.

In January 1938, with the American lease nearly up, the Irish Government decided to make the Chief Secretary's Lodge the official residence of the President of Ireland.

In the 1970s, the grounds were christened Deerfield by the wife of a United States ambassador on account of the number of deer who roam in the open parkland around the mansion (Phoenix Park).

The property consists of 62 acres of lawn, orchards and gardens on which are located the Ambassador's residence, three cottages and a security building at the front gate.

U.S. presidents John F. Kennedy, Richard Nixon, Bill Clinton, and Joe Biden have all stayed at Deerfield during Irish visits.

Security at the grounds is provided externally by the Special Detective Unit (SDU), the main counter-terrorism and counter-intelligence branch of the Garda Síochána (Irish national police), and internally by the U.S.