1853-58 Ann Pamela Cunningham spearheads the hard-fought campaign to save Mount Vernon, resulting in the purchase of the home and 200 acres.
1860-61 Extensive repairs are made to the Mansion and dependencies.
1874 The Mansion’s two colonnades are restored.
1875 Three cisterns are constructed to provide water for firefighting. A manual-powered fire engine is acquired. 1875 The Piazza and Balustrade are restored.
1878 A post office is established on the property.
1879-81 The floors and woodwork in the Mansion are restored.
1880 The Wharf is rebuilt with the support of Phoebe Apperson Hearst, Vice Regent for California, in response to the fact that the majority of visitors were arriving by boat at that time.
1885-91 Water mains for fire hoses are laid around the Mansion. Concealed underground pumping station and a hose storage vault are constructed.
1886 The Old Tomb and Summer House are restored.
1889 A system of drainage tunnels is laid in the riverfront hillside to prevent flooding and subsequent landslides. 1892 The Spinning House is restored, and the Coach House is reconstructed.
1893 The Mansion is strengthened with new timbers.1893 Ten acres of swamp near the river bank are drained and reclaimed for farm land.
1895-1901 2,150 feet of seawall is constructed along the Potomac to end dangerous erosion and landslides. The wall is made possible through the support of Phoebe Apperson Hearst.
1896 A hot water boiling and heating system is constructed away from the Mansion, significantly reducing the danger of fire.
1898 The Mansion is structurally supported by brick piers in the cellar.
1899 The Main Gate is constructed from the support of Mrs. Maxey and the people of Texas to accommodate visitors from the new electric trolley.
1902 12,000 square feet of brick-paved walkways are constructed.
1907 The water system is improved, and vaults for coal storage are constructed.
1908 The boat channel is dredged. 1910 New public restrooms (utilizing “water-closets”) are installed.
1912 The Mansion and dependency roofs are re-shingled with authentic “Dismal Swamp” cypress through a nationwide campaign to “Raise the Roof.”
1914 The flagstone on the Piazza is replaced with stone from the original quarry in England.
1922 An electric power plant (emergency generator) is constructed, and a complete electrical system designed by Thomas Edison is installed with the goal of further reducing the risk of fire.
1922-24 The Mansion roof is lined with fireproof material. A 250,000-gallon reservoir and a new pumping station are constructed, all concealed in the icehouse. Henry Ford donates the first fire engine to Mount Vernon.
1927-31 Automatic fire detection system and fire suppressant system are installed in the Mansion.
1928 The Museum is constructed.
1929 The Administration building is constructed. It would later be named for Frances Payne Bolton, former Vice Regent for Ohio.
1929 The Mansion stairway and landings are reinforced with steel beams.
1931 The Judge’s porch is removed from the south end of the Mansion.
1931 6,500 feet of brick boundary wall constructed around the Estate.
1931-33 The Mansion is completely inspected for structural soundness, strengthened with steel beams and treated against termites. Both chimneys are braced.
1932 Various brick service buildings are constructed for use by Mount Vernon staff.
1936 A new Ford fire engine is acquired.
1936 A residence for the Director is built.
1948 New concealed public restrooms are constructed.
1950-52 Two dormitory buildings for the Regent and Vice Regents to use during council are constructed and respectively named Cunningham, in honor of Ann Pamela Cunningham, and Tracy, in honor of Sarah Tracy.
1950-52 Historic Greenhouse and Slave Quarters are reconstructed on the original site with bricks from the original White House, following a major renovation of that building.
1955 Frances Payne Bolton, Vice Regent for Ohio, purchases nearly 500 acres of Maryland shoreline across the Potomac from Mount Vernon for $333,000 to prevent the commercial development of that property.
1979 Mount Vernon becomes one of the very first historic homes to undertake a comprehensive campaign of modern, scientific paint analysis using the process of microscopic paint analysis. Nearly 2,500 paint samples are taken throughout the Mansion and studied to determine the actual colors of the Mansion rooms.
1980 The overmantel in the Small Dining Room is restored. The plaster is stabilized and most of the paint from the ornamentation is removed. Along with the rest of the Mansion, the entire room is repainted to approximate the verdigris green color that was found on the walls and cornice under 17 to 24 other layers of paint.
1980-81 The entire Mansion is repainted based on the results of the microscopic paint analysis, making Mount Vernon one of the first historic homes to completely repaint based on this process and at the same time establishing a new precedent on color preferences of the eighteenth century.
1981 The library, research center, and new administration building are constructed and named in honor of Ann Pamela Cunningham.
1982 A Slave Memorial is designed by architecture students from Howard University and built on the original slave burial ground.
1989 The Main Gate is restored. Enhanced security, an air conditioning system, and modern computers for ticketing are added through the generosity of Mrs. Anderson, and the people of Texas, following in the tradition of the Texans who raised money to build the gatehouse 100 years earlier.
1990 The root cellar of the original House for Families slave quarter is excavated by Mount Vernon archaeologists, uncovering more than 65,000 artifacts that offer an intimate look at the lives of enslaved people who lived and worked at Mount Vernon. The site provides one of the most important sources of information on eighteenth-century slave life in the Chesapeake region.
1991-96 An exact replica of George Washington’s 16-sided treading barn is rebuilt to General Washington’s specifications, using 18th-century techniques and tools. The barn becomes the centerpiece of the five-acre George Washington: Pioneer Farmer site, which reveals a lesser-known side of General Washington - that of an innovative farmer. The 16-sided barn is heralded as the most accurately reconstructed 18th-centruy agricultural building in the country.
1993 The Mansion’s Cupola is restored through the support of Eugenia R. Seamens, Regent and Vice Regent for Massachusetts and the people of that state.
1996-2002 George Washington’s Gristmill, which was reconstructed on its original foundation by the state of Virginia in 1933, is restored by Mount Vernon, returned to full working order, and again becomes a part of the Estate.
1996-present The foundation of George Washington’s Distillery, adjacent to the Gristmill, is uncovered by Mount Vernon archaeologists. The Distillery will be rebuilt on the original foundation, and is expected to open in 2005.
2001 The Dung Repository is rebuilt on its original foundation adjacent to the Mansion. Designed to compost horse manure and other organic waste for fertilizer, it had a 32 feet x 12 feet cobblestone floor and a roof supported by posts set in the ground. The original floor was is such good shape that it serves as the floor of the re-built structure.
2001-2002 The Small Dining Room is the subject of a major restoration effort. Further advancement in the field of paint analysis allows for an even more accurate representation of the original color of the room. Mount Vernon’s restoration staff uncovers hidden details including the original layout lines inscribed by the "French Stucco Man" in 1775, details not seen in more than 225 years.
2003-2005 The automated milling system designed by Oliver Evans that was first installed in Washington’s mill in 1791 is reconstructed and made fully operational.
2004-2006 The Donald W. Reynolds Museum and Education Center and the Ford Orientation Center, located adjacent to the Texas Gate, are constructed and opened to the public. The Orientation Center serves as the starting point for a visit to the Estate, including an 18-minute introductory film. The Museum and Education Center presents a multi-media experience, with 23 galleries and theatre spaces that together illuminate the detailed story of Washington’s entire life.
2005-2007 The Distillery is reconstructed on the original site and is opened to the public as an operating replica of the 18th-century building. # 2006-2008 The former security building on the North Lane is restored and opened for interpretation as the Gardener’s House; this is the last 18th-century building on the estate to be restored to its period appearance.
2007 A log cabin modeled after the buildings that were used to house slaves at the Mount Vernon outlying farms is constructed at the George Washington: Pioneer Farmer site; the structure is used to interpret the daily lives of the slaves who worked as field hands.
2008-2009 The Porter’s Lodges at the West Gate, built in 1875-76, are restored and a sign and an exhibit panel are installed to interpret the history of the buildings and the gate.
2009 The Blacksmith Shop on the North Lane is reconstructed on the site of the original building, first constructed in 1768, and it is opened to the public as a fully operational replica.