Holt House is a historic house on the grounds of the National Zoo in Washington, D.C.. Thought to have been built before 1814, it is one of the most important examples of early Neoclassical architecture in the city, and was one of the major houses in Washington, D.C., when it was built. Since 1889, its caretaker has been the Smithsonian Institution. It has been left vacant since the 1980s.

In 1964, Holt House was listed in the District of Columbia Inventory of Historic Sites and on the National Register of Historic Places on April 24, 1973 with the following National Register of Historic Places comment on it:

History Holt House is intimately linked to the early history of both Washington and the nation through its association with such prominent figures as Thomas Johnson (first governor of Maryland), Thomas Jefferson, Benjamin Stoddert (first Secretary of the Navy), Benjamin Mackall (Georgetown merchant), John Adams, John Quincy Adams, and Andrew Jackson. It has been owned by the Smithsonian Institution since 1890, and is the oldest building under its auspices.

While Holt House is one of the great country-style estates built during the early years of the new Federal City, it remains a mystery as to who built it and when. The chain of ownership and the backgrounds of the owners of the land on which the house sits suggest it could have been constructed no later than 1814. It seems most likely that the house was built by George Johnson, and if so, his connections to Dr. William Thornton, first Architect of the Capitol, suggest that Thornton may have a hand in the design of Holt House.If the house were built before George Johnson, through Thornton's positions as a City Commissioner, Director of the Bank of Columbia, and as a Quaker, Thornton also had connections with the previous owners of the property before the Johnsons (Benjamin Stoddert, Walter Mackall, and Jonathan Shoemaker), indicating that he was probably familiar with the property even before a house was constructed on it.

Benjamin Stoddert The land on which Holt House sits was originally part of a tract of land acquired from the Beall family in 1793 by Benjamin Stoddert, builder of Halcyon House in Georgetown. Stoddert served as a captain in the Continental Army during the American Revolutionary War, Secretary of the Board of War (1779–1781), a merchant owner in Georgetown, co-founder and President of the Bank of Columbia (1794), and first Secretary of the Navy. It is likely that Stoddert built Columbia Mills on the property in the 1790s.From a personal letter by Mrs. Rebecca Stoddert it is known that Stoddert owned a mill in the District of Columbia. Since no other mill property has been traced to the Stodderts in D.C., it is therefore assumed that Stoddert constructed the Columbia Mills and that the "buildings, improvements" refer to Columbia Mills. District of Columbia Recorder of Deeds, Land Records Liber F6, folio 95-97. Personal letter to Eliza Gantt from Rebecca Stoddert, August 4, 1799. Library of Congress, Manuscript Division, Personal Papers of Rebecca S. Stoddert. Despite his prominent position, Stoddert's land speculation left him land rich and cash poor. Perhaps to help increase his cash flow, he constructed a flour mill on the land surrounding Holt House.

Walter Mackall In December 1800, Stoddert sold the property, referred to as "Pretty Prospect" to his friend Walter Mackall. The deed included "the buildings, improvements, privileges, advantages and appurtenances."D.C. Recorder of Deeds, Land Records F6, folio 95-97. These "buildings" may be a reference to only the mill structures, but may also have included some form of a residence for a mill manager. Architectural evidence suggests that the west wing of Holt House may have been built earlier than the rest of the house and may have served as a small residence. If a house the present size of Holt House existed at this time, it would have been significant enough a structure to be mentioned separately in the deed.

Walter Mackall came from Calvert County, Maryland, served in the Maryland House of Delegates, and was a wealthy land holder in both Maryland and Washington. His brother, Benjamin Mackall, married Christina Beall, whose father Brooke Beall, was a wealthy shipping merchant in Georgetown, sending great quantities of grain and tobacco to England. When the government moved to Washington in 1800 and when William Thornton was serving as City Commissioner, Benjamin Mackall was one of those in charge of the transfer of the government books from Philadelphia.Sally Somervell Mackall. Early Days Of Washington, 1899 Benjamin may have become involved in the milling part of his father-in-law's business. To his daughter Christina, Beall gave a double square on Georgetown Heights, part of his vast landholdings known as the "Rock of Dumbarton," where they built Mackall Square.

Walter Mackall owned Pretty Prospect for only four years. He may have originally taken an interest in the mills due to his brother Benjamin's connection to the Beall family business. This was also a period of great land speculation in the new Federal City, and the time when large country-style houses were being constructed in Georgetown and on the outskirts of the City. Mackall may have built the present house or expanded a smaller, pre-existing house on speculation of increased resale value.

Jonathan Shoemaker In 1804, Mackall sold the property, which consisted of the existent "mills, mill seats, way waters, buildings, and improvements"Land Transfer Deed from Walter Mackall to Jonathan Shoemaker. D.C. Recorder of Deeds, Land Records K10, folio 117-118) also DC Recorder of Deeds, Land Records W22, folio 112. to Pennsylvania Quaker and miller Jonathan Shoemaker for $3,800 with an additional mortgage for a total cost $9,600. He arrived with his family of five sons and one daughter to operate the mills. While the deed acquired by Shoemaker now mentions the mills, it still does not refer to a house on the property. Problems at Columbia Mills and a dispute with Thomas Jefferson forced the Shoemakers to sell the property and relocate to Shadwell, Virginia to help operate Jefferson's mills there.

The Shoemakers were among the earliest Quaker settlers in the area and traveled far to attend meetings. As a former Quaker, Mrs. Roger Johnson may have known Jonathan and Elizabeth Shoemaker as they may have attended the same Quaker meetings in Indian Springs, Maryland. When the first Quaker Meeting was held in Georgetown in 1806, the Shoemakers may have made the acquaintance of architect William Thornton then, but sold the property only three years later."Records Relating to Pre-National Zoological Park Purchases." Smithsonian Institution Archival and Historic Preservation Division. Available at: http://www.si.edu/oahp/holthous/pz1834on.htm.

The fact that Shoemaker took a mortgage to acquire the property and sold it for less than his original purchase price suggests that he was not in a financial position at this time to construct a larger manor house the size of Holt House, had it not already existed when he bought the property. Additionally, his Quaker beliefs would suggest a more modest lifestyle, as he relied on his family and not employees or slaves to run the mills, and would not have allowed for managing a house of this size as well. Ultimately, the Shoemaker family was prosperous, and Pierce Shoemaker returned to Washington and purchased what is known today as Peirce Mill on Rock Creek Park.

Roger Johnson In 1809, Jonathan Shoemaker sold the property for $7,500 to Roger Johnson, of Frederick County, Maryland,Land Transfer Deed from Jonathan Shoemaker to Roger Johnson. D.C. Recorder of Deeds, Land Records W22, folio 109-111.7. James Dunlop Papers. Record Book 1809–1919. Maryland Historic Society. MS 316. the younger brother of Maryland's first governor, Thomas Johnson. This was an investment on Roger's part, as he already owned two foundries, a glass works, and a plantation in Frederick County and remained at his home "Bloomsbury" in Frederick County, while sending his son George to manage Columbia Mills.

Around 1809 or 1810, George Johnson is wed to Elizabeth Dunlop, daughter of wealthy Georgetown merchant James Dunlop, and the niece of Thomas Peter (the builder of Tudor Place and designed by Dr. William Thornton). There is evidence that George was married by 1810 and may have been living at the mill property by then, as Mrs. Dunlop (George's mother-in-law) sent three house slaves to her daughter in that year,James Dunlop Papers. Record Book 1809–1919. Maryland Historical Society. MS 316 which would probably not have occurred were they living with the Dunlops.

Beginning in 1812, George Johnson began borrowing large sums of money in order to rebuild the mills after they burned, employing a millwright to build "the best mill possible,"Roberta Johns Peter. "The Johnson Family." Maryland Historical Society, n.d. and possibly may have used some of this money to construct a new house, or enlarge an existing house on the property as well. Perhaps the first reference to a "house" on the property appears in an 1818 letter from George Johnson to his father-in-law, James Dunlop.Letter from George Johnson to James Dunlop, 21 Dec 1818. Dunlop Papers 1788–1908. Maryland Historical Society. He was concerned that the house (which he refers to in the letter as "my house," "in town") would be attached with a lien due to his large debts, and was in hopes of renting it out. Possibly, George owned another house in Georgetown at that time as well. While "in town" in present-day terms generally refers to an urban center, because George Johnson is writing from Frederick, he may be referring to Washington in general. There have been no records discovered to-date that show any evidence of another residence for George Johnson other than Pretty Prospect. George's financial problems, beginning as early as 1814, suggest that he was not in a position to construct a large house after about 1812, due possibly in part to the financial impact of the British blockade of the Chesapeake Bay and the Potomac at that time.

In 1818, due to the extent of George's debts, Roger Johnson attempted to intervene on behalf of his son. Only two days after George's letter from Frederick, Roger also writes to James Dunlop. In his letter to Dunlop, he says that he hopes to sell his lot near the mill in the spring, then later to "sell the half of his Mil" (which he never did). Roger also asks James Dunlop to assume payment on half of George's debts, as he considered him partially responsible as the under signer of the loans.Letter from Roger Johnson to James Dunlop, 23 Dec 1818. Dunlop Papers 1788–1908. Maryland Historical Society. In his letter to Dunlop, Roger makes no separate reference to a house, only to the lot near the mill. But, according to Smithsonian records, a month before this letter was sent, Roger had already transferred the deed for the mill to the Bank of Columbia, with George's father-in-law, James Dunlop serving as trustee "to set up and sell at public sale for cash or upon credit" against George's debts, which totaled $28,161.55 with interest. The deed transfer encompassed "the Mill houses, dwelling houses, buildings, improvements."Roger Johnson deed transfer to transfer to James Dunlop of the Bank of Columbia. 1818. D.C. Recorder of Deeds, Land Records AT44, folio 39-42. Roger maintained possession of 13 acres of Pretty Prospect, which later become the Holt House property.