- 1654 Thomas Pell signs treaty with Siwanoy Indians for about 9,000 acres in what is now the Bronx and Lower Westchester.
- 1664 The Dutch hand over New York land to the English.
- 1666 A land grant is issued to the Manor of Pelham by the first English Governor of New York, Richard Nicholls. Thomas Pell is named First Lord of the Manor.
- 1790 The property is sold to John Bartow, husband of Ann Pell. The original Pell Manor was likely destroyed during the American Revolution but the Bartows had a house on the property.
- 1813 Property ownership leaves the Bartow-Pell family. Land tracts sold by John Bartow to Herman Leroy, a wealthy merchant.
- 1836 Robert Bartow, grandson of John Bartow, resumes ownership of the property. This working farm becomes an estate with the present Mansion and Carriage House built by 1842.
- 1842-1888 Beginning with Robert Bartow and his family, the estate is occupied by Bartow descendants for the next four decades.
- 1888 The Bartow heirs sell the estate and grounds to the City of New York for inclusion in the future Pelham Bay Park.
- 1888-1913 The Mansion is abandoned after it was used by various private and charitable organizations. It is the only estate in the Pelham Bay community that was not demolished by mid-century.
- 1914 The Mansion is leased by the City of New York to The International Garden Club. Mrs. Charles Frederick Hoffman was the club founder and president.
- 1915-1918 The Mansion is restored and formal gardens are designed by Delano & Aldrich.
- 1936 Mayor LaGuardia uses the Mansion as his summer office.
- 1938 Included on the National List of Buildings Worthy of Preservation.
- 1946 The Mansion interiors are refurbished with period objects under the direction of Joseph Downs, Curator of the Henry Frances Dupont Winterthur Museum in Delaware. The Mansion is reopened to the public as the Bartow Mansion Museum and Gardens.
- 1959 The name Pell is added to acknowledge the importance of the Pell family in the estate's history.
- 1993 Reopening of the Carriage House which was restored to its original use as a working stable.
- 1966 Designated a New York City Landmark.
- 1974 Mansion and the Carriage House are entered on the National Register of Historic Places.
- 1975 Principle interior rooms of the Bartow-Pell Mansion Museum are designated a Landmark by the City of New York Landmarks Preservation Commission.
- 1977 Designated a National Historic Landmark.
- 1978 Designated an expanded Landmark Site by the City of New York Landmarks Preservation Commission to include the Carriage House, the walled gardens, and a small family memorial plot.