Question: When did the first Walmart open in the state where Knocks Folly is located?

full_context: Document 1: Walmart: Walmart Inc. Walmart's current logo since 2008 Walmart's official headquarters in Bentonville, Arkansas Formerly called Wal - Mart, Inc. (1969 -- 70) Wal - Mart Stores, Inc. (1970 -- 2018) Type Public Traded as NYSE: WMT DJIA component S&P 100 component S&P 500 component ISIN US9311421039 Industry Retail Founded July 2, 1962; 55 years ago (1962 - 07 - 02) Rogers, Arkansas, U.S. Founder Sam Walton Headquarters Bentonville, Arkansas, United States Number of locations 11,718 stores worldwide (January 31, 2018) Area served Worldwide Key people Greg Penner (Chairman) Doug McMillon (President & CEO) Products Electronics Movies and music Home and furniture Home improvement Clothing Footwear Jewelry Toys Health and beauty Pet supplies Sporting goods and fitness Auto Photo finishing Craft supplies Party supplies Grocery Services Walmart - 2 - Walmart Walmart MoneyCard Pickup Today Walmart.com Walmart Pay Revenue US $500.34 billion (2018) Operating income US $20.437 billion (2018) Net income US $9.862 billion (2018) Total assets US $204.52 billion (2018) Total equity US $77.869 billion (2018) Owner Walton family (51%) Number of employees 2.3 million, Worldwide (2017) 1.4 million, U.S. (2017) Divisions Walmart U.S. Walmart International Sam's Club Global eCommerce Subsidiaries Walmart Canada Walmart Mexico Walmart Chile Walmart de México y Centroamérica @ WalmartLabs Walmart Neighborhood Market Asda Amigo Supermarkets Vudu Massmart Seiyu Group Bompreço Líder Jet.com Hayneedle Moosejaw ModCloth Flipkart Website Corporate website Commercial website Footnotes / references
Document 2: History of Walmart: In April 1983, the company opened its first Sam's Club store, a membership - based discount warehouse club, in Midwest City, Oklahoma. They also expanded into Indiana, Iowa, New Mexico, and North Carolina and implemented ``people greeters ''in all of their stores. The first stores opened in Virginia in 1984.
Document 3: Sam's Club: As of January 31, 2018, Sam's Club operates 597 membership warehouse clubs in 44 U.S. states. Alaska, Massachusetts, Oregon, Rhode Island, Vermont, and Washington are the only states where Sam's Club does not operate, as is the case for the District of Columbia. Walmart International also operates Sam's Clubs in Mexico, Brazil, and China. It has 162 locations in Mexico, 27 locations in Brazil, and 19 in China. Locations generally range in size from 94,000 -- 161,000 sq ft (8,700 -- 15,000 m), with an average club size of approximately 134,000 sq ft (12,400 m).
Document 4: Knocks Folly: Knocks Folly, also known as Janvier House and Barroll House, is a historic home located at Kennedyville, Kent County, Maryland, United States. It is an unusual combination of a small, -story, mid-18th-century log home with a three-story, Federal brick wing.
Document 5: History of Walmart: In 1991, the company expanded into Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, and New York. Walmart expanded worldwide this year, with the opening of their first store outside the United States in Mexico City. They also acquired Western Merchandisers, Inc. of Amarillo, Texas. 1991 also saw the launch of the Sam's American Choice brand of products.
Document 6: Bowman's Folly: Bowman's Folly, also known as Montpelier, is a historic home located near Accomac, Accomack County, Virginia. It was built about 1815, and has a 2 1/2-story, main block with a 1 1/2-story wing. The main block has brick ends with interior end chimneys and frame fronts on the north and south. It has a gable roof with dormers. The front facade features a Palladian window and pedimented entrance porch. Also on the property are a frame kitchen, now connected to the main house by a hyphen; frame dovecote, and frame privy.
Document 7: History of Walmart: By 1977, Wal - Mart expanded into Illinois and made its first corporate acquisition, assuming ownership and operation of the Mohr - Value stores, which operated in Missouri and Illinois. This was followed by the acquisition of the Hutcheson Shoe Company in 1978. In the same year Walmart also branched out into several new markets, launching its pharmacy, auto service center, and jewelry divisions.
Document 8: Ludwick Rudisel Tannery House: The Ludwick Rudisel Tannery House, also known as Motter Place, is a historic home located at Taneytown, Carroll County, Maryland, United States. The main block is constructed of brick on a fieldstone foundation, five bays in length, two deep, with an original slate roof, built about 1807. Attached is a two-story, two-bay-long brick kitchen. The house features Georgian massing and fine Federal detailing.
Document 9: Rokeby (King George, Virginia): Rokeby is a historic home located at King George, King George County, Virginia. The original section was built about 1828, and is a two-story, three bay Federal style brick dwelling. It has a low hipped roof, tripartite windows, lintel-type
Document 10: Jacob Highbarger House: The Jacob Highbarger House was built "circa" 1832 in Sharpsburg, Maryland, United States. The Greek Revival-influenced house is a late example of limestone construction in the Cumberland Valley of Maryland, with an attached log workshop. The log structure is an unusual example of corner-post log construction with diagonal bracing.
Document 11: Ditto Knolls: Ditto Knolls is a historic home and farm located near Hagerstown, Washington County, Maryland, United States. It was built about 1790, and is a five-bay, two-story brick house with a two-bay, one-story brick rear wing. It features a one-story entrance porch supported by Doric columns. Also on the property is a large stone bank barn and springhouse. It is one of two historic farm complexes located in Ditto Farm Regional Park, along with the Henry McCauley Farm.
Document 12: History of Walmart: By 1988, Walmart was operating in 27 states, having expanded into Arizona, Michigan, Ohio, West Virginia, New Jersey, and Wyoming. By 1990, they expanded into California (which marked Walmart officially becoming a fully nationwide retailer), Nevada, North Dakota, Pennsylvania, South Dakota, and Utah. The Walmart Visitor's Center also opened this year on the site of Sam Walton's original store.
Document 13: Walmart: Walmart U.S. is the company's largest division, accounting for US $298.38 billion, or 62.3 percent of total sales, for fiscal 2016. It consists of three retail formats that have become commonplace in the United States: Supercenters, Discount Stores, Neighborhood Markets, and other small formats. The discount stores sell a variety of mostly non-grocery products, though emphasis has now shifted towards supercenters, which include more groceries. As of January 31, 2018, there are a total of 4,761 Walmart U.S. stores.
Document 14: History of Walmart: In 1981, Wal - Mart expanded into the southeastern US market, opening stores in Georgia and South Carolina, and acquiring 92 Kuhn's Big K stores. They expanded into Florida and Nebraska in 1982.
Document 15: Enoch Jones House: Enoch Jones House, also known as "Boxwood," is a historic home located near Clayton, Kent County, Delaware. It dates to the mid-18th century, and consists of a two-story, three bay, brick main house with a lower two-story frame west wing. The house is in the hall-and-parlor plan. It has a gable roof on both sections. The first documented reference to the house is a 1792 survey of Enoch Jones 717-acre estate.
ground_truth: 1991
sub_queries: What state is Knocks Folly located? Answer: Maryland
when did the first walmart open in Maryland Answer: 1991