Question: When did the first Walmart open in the state where Coppin State University is located?

full_context: Document 1: Coppin State University: Coppin State University is a public historically black university located in Baltimore, Maryland, United States. It is part of the University System of Maryland. The University is a member-school of the Thurgood Marshall College Fund.
Document 2: Houston: Four separate and distinct state universities are located in Houston. The University of Houston is a nationally recognized Tier One research university, and is the flagship institution of the University of Houston System. The third-largest university in Texas, the University of Houston has nearly 40,000 students on its 667-acre campus in southeast Houston. The University of Houston–Clear Lake and the University of Houston–Downtown are stand-alone universities; they are not branch campuses of the University of Houston. Located in the historic community of Third Ward is Texas Southern University, one of the largest historically black colleges and universities in the United States.
Document 3: 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 4: Marshall University: Marshall University is a public research university in Huntington, West Virginia. It was founded in 1837 and is named after John Marshall, the fourth Chief Justice of the United States.
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: 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 7: Broadcasting Archives at the University of Maryland: The Broadcasting Archives at the University of Maryland is home to several collections – the National Public Broadcasting Archives and the Library of American Broadcasting among them – housed together on the campus of the University of Maryland in College Park. Among the other holdings is the unusual Art Gliner Humor Collection, since humor plays such an important part in the history of radio and television programming.
Document 8: Thurgood Marshall College: Thurgood Marshall College (TMC) is one of the six undergraduate colleges at the University of California, San Diego. The college, named after Thurgood Marshall, the first African-American Supreme Court Justice and lawyer for the landmark 1954 Supreme Court case Brown v. Board of Education, emphasizes "scholarship, social responsibility and the belief that a liberal arts education must include an understanding of [one's] role in society." Marshall College's general education requirements emphasize the culture of community involvement and multiculturalism; accordingly Marshall houses the minors in Public Service and Film Studies for the campus. Significant academic programs and departments have come out of the college over many decades: Communication, Ethnic Studies, Third World Studies, African American Studies, Urban Studies & Planning, and Education Studies.
Document 9: Winston-Salem State University: Winston-Salem State University (WSSU), a constituent institution of the University of North Carolina, is a historically black public research university located in Winston-Salem, North Carolina, United States. It is a member-school of the Thurgood Marshall College Fund. WSSU is an accredited university offering baccalaureate and graduate programs to a diverse student population.
Document 10: 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 11: Baltimore City Community College: Baltimore City Community College (BCCC) is the only community college in the city of Baltimore, Maryland, United States and the only State-sponsored community college in Maryland. It is accredited by the Middle States Commission on Higher Education (MSCHE). It was founded in 1947 and has about 5,000 students enrolled in one of its campuses. While BCCC primarily serves the residents and business community of Baltimore, it also offers educational opportunities on all levels to the citizens of Baltimore and the State of Maryland that enables students to obtain good jobs, transfer to four-year colleges, or take short-term training to upgrade their skills or acquire new ones.
Document 12: 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 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: 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 15: 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.
ground_truth: 1991
sub_queries: In which state is Coppin State University located? Answer: Maryland
when did the first walmart open in Maryland Answer: 1991