Question: When did the first Walmart open in the state where Hidden Valley Farm is located?

full_context: Document 1: John Walter Farmstead: John Walter Farmstead, also known as Lengauer House, is a historic home located in Washington Township, Westmoreland County, Pennsylvania. The house was built in 1848, and is a two-story, "L"-shaped red brick dwelling, five bays wide in the Greek Revival style. It has a low-pitched, slate covered gable roof. The front facade has a three bay, hipped roof porch. Associated with the house is a contributing bank barn, built about 1846, and spring house, built in 1912.
Document 2: Routzahn-Miller Farmstead: The Routzahn-Miller Farmstead is a historic home and farm complex located at Middletown, Frederick County, Maryland, United States. It consists of a Federal style-influenced brick house and smokehouse, both built about 1825; a later frame out-kitchen / washhouse; a standard Pennsylvania barn; a 20th-century dairy barn and milk house; and a 20th-century equipment shed. The Pennsylvania barn was probably built in the late 19th century and was recently rehabilitated for use as a preschool. The complex is located on a parcel on the east flank of South Mountain. It is representative example of a type of domestic and agricultural grouping which characterized the rural mid-Maryland region from the early 19th century through World War II era.
Document 3: 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 4: 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 5: 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 6: 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 7: Baldwin, Maryland: Baldwin is an unincorporated community in Baltimore County, Maryland, United States. The United States Postal Service has assigned Baldwin the ZIP Code 21013. Until 1958, this community was served by the Maryland and Pennsylvania Railroad at milepost 18.4. Hidden Valley Farm was listed on the National Register of Historic Places in 1983.
Document 8: 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 9: Applewood Farm: Applewood Farm is a farmstead in Ledyard, Connecticut, United States. Constructed in 1826 by Russel Gallup, the farmhouse was built with a colonial center chimney design with Federal style details that has been modernized to the early 20th century without significantly changing the floor plan. Named after the apple orchards planted by Russel Gallup, Applewood Farm developed significantly under the ownership of Everett Gallup, the last member of the family to own the property. The property was later owned by Arlene Meyer Cohen and a 40-acre parcel was sold off in November 1984. After the Betz family became the owners it was added to the National Register of Historic Places and operated as a bed and breakfast through the 1990s. In 1987, the property included five contributory structures, the farmhouse, corn crib, barn, silo and chicken coop. The property also has one non-contributing structure, a machinery shed from the 1960s.
Document 10: 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 11: 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 12: Hunt Valley, Maryland: Hunt Valley is an unincorporated community in Baltimore County, Maryland, United States. Its traditional name was based on being just east of Maryland's traditional Horse Country (like the Kentucky Blue Grass region), and the site of the venerable Maryland Hunt Cup championship of steeplechase horse racing and jumping established 1894. It lies just north of the city of Baltimore, along the York Road (former old historic Baltimore-York Turnpike) which is now Maryland Route 45 off Interstate 83. The Loch Raven Reservoir nearby is an important drinking water resource and with its surrounding forested watershed is one of three reservoirs (Loch Raven, Prettyboy and Liberty) established for the City of Baltimore and its surrounding metropolitan areas in Baltimore County since the 1880s and expanded in the 1910s. Located at a latitude of 39.5° North and longitude 76.7° West.
Document 13: 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 14: Hidden Valley Farm: Hidden Valley Farm is a historic home and farm complex located at Baldwin, Harford County, Maryland, United States. It consists of a mid-19th century vernacular Greek Revival brick farmhouse with several auxiliary structures. The house is a three-story, rectangular brick dwelling with a gable roof, with a two-story wing. The house features square-columned one-story porches across the façade and both sides of the wing. Also on the property are a mid-19th century barn, summer kitchen, and smokehouse, and later wood shed and garage.
Document 15: Providence Plantation and Farm: Providence Plantation and Farm, also known as Fogg House and Farm, is a historic plantation house located near Newtown, King and Queen County, Virginia. The main was built about 1826, and altered about 1840. It is a two-story, three bay, brick house with Federal style design influences. Also on the property are the contributing two-story Reconstruction-era granary and carriage house, and Great Depression-era hen laying house, two-story sweet potato shed, and mechanic's shop.
ground_truth: 1991
sub_queries: In which state is Hidden Valley Farm located? Answer: Maryland
when did the first walmart open in Maryland Answer: 1991