Two years after serving as the first president of the United States, George Washington dies at age 67 on December 14. By the terms of Washington’s will, the first president grants his wife Martha “the use, profit and benefit of my whole Estate, real and personal, for the term of her natural life.”

Martha Dandridge Custis Washington dies at age 70 at Mount Vernon.

Following the transfer of Pennsylvania’s state capital to Lancaster in 1799, Independence Hall is threatened by development. The city of Philadelphia purchases the landmark to save it from demolition.

In accordance with Washington’s will, a new family burial vault is completed, and Washington’s body, along with the remains of Martha Washington and other family members, is transferred to the New Tomb.

A tremendous fire devastates Washington’s greenhouse and a portion of the enslaved living quarters.

John Augustine Washington III formally takes ownership of Mount Vernon. Though John Augustine was a motivated farmer, Mount Vernon's total acreage shrank to roughly 1,200 acres from a height of 8,000 acres during George Washington's lifetime, and the remaining farmland is not enough to adequately sustain the Washingtons. John Augustine eventually reversed Bushrod's decision to ban steamboats and entered into a contract with a company that provided regular trips from Washington, D.C., three days a week.

John Augustine Washington III finds he is financially unable to maintain Mount Vernon given the demands of upkeeping the tourist destination. The now-iconic piazza is recorded to be supported by makeshift wooden posts. After soliciting the U.S. government and the Commonwealth of Virginia for support, Washington agrees to sell the Mansion and 200 acres of surrounding land to the MVLA for $200,000.

John Augustine Washington III leaves behind a handful of original objects, including Jean Antoine Houdon’s famous lifelike sculpture of George Washington.

Hancock Manor, the home of John Hancock, is torn down in Boston. This event galvanizes early historic preservation efforts in the Northeast and begins the impetus for the modern historic preservation movement.

The Vice Regent for New Jersey from 1868 until 1891, Nancy Wade Halsted challenged the Ladies to furnish each room in the Mansion. Eighteenth-century pieces were to be used wherever possible, with more recent Greek Revival and Victorian furnishings filling the gaps. Many decades would pass before the Association could furnish all rooms with original Washington pieces or very similar examples.

Twelve founding Ladies of the Association, representing their home states, pose on the piazza with the famous Houdon bust of George Washington. Miss Cunningham, first Regent of the Ladies' Association, is seated to the right of the bust. The other ladies pictured are Vice Regents in the Association's governing council, a structure still in place today.

Mary Jeffery Galt reacts to the loss of Powhatan’s Chimney—a surviving chimney stack purported to belong to a house built by John Smith at the site of Werowomoco—by founding the Association for the Preservation of Virginia Antiquities (APVA, now Preservation Virginia).

Elizabeth A. Rathbone, Vice Regent from Michigan, raises funds in her home state for the reconstruction of Washington’s coach house. The building, which stood at the end of the south lane by April 1776, disappeared from the landscape between 1855 and 1858. Excavation uncovers the original foundations, which are repaired; oral tradition passed down by “old servants” allows Colonel Dodge to reproduce it “practically.”

This effort, along with the 1860 reconstruction of the spring house, represents the first instance of a preservation society reconstructing missing 18th-century buildings based on surviving evidence.

Harriet Clayton Comegys of Delaware served as Regent from 1909 until 1927. During her tenure, the gardens and grounds were given greater attention than ever before, marking the first concerted attempt to recapture their appearance during George Washington's lifetime.

The National Park Service is established; historic and natural sites of significance are acquired by the federal government for public visitation and use. Sites connected with George Washington are among early preservation initiatives, and the first national historic park, Washington’s wartime headquarters in Morristown, New Jersey, is designated in March 1933.

Henry Ford visits Mount Vernon and is alarmed to discover that George Washington’s wood-frame buildings are not adequately protected from fire. Ford donates the MVLA’s first fire engine—a built-to-order American-Lafrance Combination Chemical and Hose Car. Ford also encourages the MVLA to establish a fire department, and the MVLA subsequently provides housing and equipment for an onsite employee fire team. The Ford Motor Company continues to provide vehicles for Mount Vernon's motor fleet and has sponsored many educational programs, facilities, and traveling exhibits.

Annual visitation to Mount Vernon exceeds 500,000 for the first time.

The Mount Vernon Ladies’ Association places a commemorative marker noting the site of the 200-year-old slave cemetery at Mount Vernon. We believe this marker to be the earliest of its kind on a historic plantation. Despite this official recognition, the burial ground lies unattended in dense underbrush for years.

In support of the bicentennial of Washington’s birth, the Commonwealth of Virginia constructs a replica of George Washington’s Gristmill after extensive archaeological efforts relocated the foundation of the original mill.

The MVLA reconstructs George Washington’s greenhouse and slave quarters complex, which burned in 1835. The structure incorporates 18th-century materials from a number of demolished structures in the region, most notably bricks salvaged from the original White House.

In 1962, one interior bunkroom is refurnished and opened to the public, one of the nation's first interpretations of an enslaved dwelling space.

The National Park Service initiates a limited register of National Historic Landmarks, the precursor of the National Register of Historic Places. Mount Vernon is added in October 1966.

Congress passes the National Historic Preservation Act in response to the Federal Aid Highway Act of 1956 and the Urban Renewal Program of the early 1960s, both of which brought about unprecedented loss of historic resources in America’s cities, culminating in the demolition of New York’s Pennsylvania Station in 1963.

Howard University architecture students design a memorial to the enslaved individuals buried at Mount Vernon’s slave cemetery. A cooperative effort between Black Women United for Action and the MVLA, the memorial raises greater awareness of the impact of plantation slavery at the home of the first president, resulting in ongoing efforts to educate the public about Washington’s conflicted relationship with slave ownership.

Mrs. Clinton M. Bockstoce, Vice Regent for Connecticut, donates funds to establish a permanent archaeology program at Mount Vernon. This action provides permanent operating funds for a research division at Mount Vernon, which had been absent since 1939. The department is expanded in 1994 to include full-time staff dedicated to architectural conservation, as well as research.

The four-acre Washington Farm is opened at Mount Vernon, inviting guests of all ages to learn more about Washington's progressive agricultural practices. The Farm represents the more than 3,000 acres Washington cultivated during the second half of the 18th century.

George Washington designed an innovative 16-sided barn to streamline the time-consuming processing of wheat. In 1870 the treading barn was near collapse. Mount Vernon's carpenters completed a replica and opened it to visitors in 1996, after five years of intensive research and construction. Major support was provided by the W.K. Kellogg Foundation. Today, the barn is the centerpiece of Mount Vernon's four-acre Washington Farm.

Having acquired the reconstruction of Washington’s Gristmill from the Commonwealth of Virginia in 1997, Mount Vernon completes a five-year restoration to return the gristmill to operational status.

A reconstruction of George Washington’s Distillery, rebuilt as close as possible to its original specifications, is completed after 9 years of historical and archaeological research. These efforts were supported by the members of the Distilled Spirits Council of the United States. Originally created in 1797, the Distillery produced nearly 11,000 gallons just two years later, making it one of the largest whiskey distilleries in America. Although the Distillery building burned in 1814, archaeological excavations uncovered its stone foundation, the location for the five stills and boiler, numerous underground drains, and evidence for the wall that separated the storeroom and office.

A reconstruction of the Blacksmith Shop, built on its original site, is completed. An excavation by Mount Vernon’s archaeologists, along with period paintings and other primary sources, provided valuable clues about the structure’s design. The Blacksmith Shop was essential to the running of the plantation and vital to Washington’s business endeavors. Records indicate that as early as 1755 a blacksmith shop was located along the north lane, about 200 feet from the Mansion.

The Upper Garden is reopened to guests after considerable archaeological and historical investigation.

Mount Vernon develops a cutting-edge prototype for a Historic Building Information Management (HBIM) system, a digital tool to understand how George Washington’s iconic Mansion was created and has evolved over time through renovations, additions, and repairs.

In 2015, this project won Mount Vernon a Special Achievement in GIS (SAG) Award.

More than 200 years after the general wrote of his dream for a library, the Mount Vernon Ladies' Association completes the George Washington Presidential Library at Mount Vernon. The 45,000-square-foot facility safeguards original books and manuscripts according to the highest standards.

Mount Vernon establishes a database compiling all references to enslaved people at Mount Vernon and other Washington properties. More than 900 individuals have been identified, with more than 500 at Mount Vernon.

After more than two years of intense forensic investigations, documentary and material culture research, conservation, and restoration, one of Mount Vernon’s major bedchambers, the Chintz Room, is reopened for viewing. Located on the second floor in the southwest corner, the Chintz Room was one of the finest of the six primary bedchambers at Mount Vernon.

After a multi-year restoration project, George and Martha Washington's Front Parlor is reopened to the public. Once a site of formal entertainment, the Front Parlor was rejuvenated with the assistance of architectural forensic analysis and significant documentary discoveries.

Mount Vernon’s Preservation and Curatorial teams complete a multiyear research and restoration project of the Central Passage, utilizing the latest documentary evidence, paint analysis, and the expertise to present its appearance in 1799. As a result of this work, visitors today experience a brighter, airier space, enlivened by numerous architectural and artistic references to Roman antiquity.

Mount Vernon unveils the results of a multi-year project to restore the Lafayette Room to its 1799 appearance. As the largest room on the second floor outside of the Washingtons’ own bedchamber, the Lafayette Room was one of the more desirable guest spaces for 18th-century visitors to Mount Vernon.

Mount Vernon launches the Mansion Revitalization Project, a landmark, multi-faceted preservation project to safeguard the Mansion’s original building fabric and ensure its structural integrity for generations to come. This includes Designing and installing a new heating/ventilation/air conditioning system (HVAC) for the Mansion, improving drainage in and around the Mansion's cellar, and repairing sections of the Mansion’s framing and masonry. This multi-stage project is anticipated to require at least three years to complete.