Question: What county is the city of Clayton found in, in the state that had the first Aldi store in the US?

full_context: Document 1: IKEA: Amid a high level of success, the company's West German executives accidentally opened a store in Konstanz in 1973 instead of Koblenz. Later that decade, stores opened in other parts of the world, such as Japan (1974), Australia, Canada, Hong Kong (1975), and Singapore (1978). IKEA further expanded in the 1980s, opening stores in countries such as France and Spain (1981), Belgium (1984), the United States (1985), the United Kingdom (1987), and Italy (1989). The company later expanded into more countries in the 1990s and 2000s. Germany, with 53 stores, is IKEA's biggest market, followed by the United States, with 48 stores. At the end of the 2009 financial year, the IKEA group operated 267 stores in 25 countries. The first IKEA store in Latin America opened on 17 February 2010 in Santo Domingo, Dominican Republic. As of July 2013, the company's presence in developing countries remains minimal.
Document 2: Clayton Township, Adams County, Illinois: Clayton Township is one of twenty-two townships in Adams County, Illinois, United States. As of the 2010 census, its population was 1,027 and it contained 465 housing units.
Document 3: Summit Township, Clay County, Iowa: Summit Township is a township in Clay County, Iowa, USA. As of the 2000 census, its population was 452. Spencer Municipal Airport is located in the township.
Document 4: Aldi: Aldi started to expand internationally in 1967, when Aldi Süd acquired the grocery chain Hofer in Austria; Aldi Nord opened its first stores abroad in the Netherlands in 1973, and other countries followed. In 1976, Aldi opened its first store in the United States in Iowa, and, in 1979, Aldi Nord acquired Trader Joes. After German reunification and the fall of the Iron Curtain, Aldi experienced a rapid expansion. The brothers retired as CEOs in 1993; control of the companies was placed in the hands of private family foundations, the Siepmann Foundation (Aldi Süd) and the Markus Foundation (Aldi Nord, Trader Joe's).
Document 5: Clayton, Missouri: Clayton is a city in and the county seat of St. Louis County, Missouri, United States, and borders the city of St. Louis. The population was 15,939 at the 2010 census. The city was organized in 1877 and is named after Ralph Clayton, who donated the land for the courthouse. The city is known for its multiple skyscrapers in its business district.
Document 6: Clay City Township, Clay County, Illinois: Clay City Township is one of twelve townships in Clay County, Illinois, USA. As of the 2010 census, its population was 1,287 and it contained 649 housing units.
Document 7: Dow City, Iowa: Dow City is a city in Crawford County, Iowa, United States, along the Boyer River. The population was 510 at the 2010 census.
Document 8: Aldi: Country Name Aldi group Since Outlets Germany Aldi Nord 1961 2,298 Aldi Süd 1962 1,880 Australia Aldi Süd 480 Austria Hofer Süd 1968 470 Belgium Aldi Nord 1973 457 Denmark Aldi Nord 1977 222 France Aldi Marché Nord 891 Hungary Aldi Süd 2008 130 Ireland Aldi Süd 1999 130 Luxembourg Aldi Nord 1990 12 Netherlands Aldi Nord 491 Poland Aldi Nord 2008 118 Portugal Aldi Nord 2006 48 Slovenia Hofer Süd 2005 80 Spain Aldi Nord 2002 264 Switzerland Aldi Suisse Süd 2005 190 United Kingdom Aldi UK Süd 1990 740 United States Aldi US Süd 1976 1,670 total number of Aldi Nord stores 4,789 total number of Aldi Süd stores International 3,880 total number of Aldi Süd stores 5,760 combined total of Aldi stores 14,429
Document 9: Clayton, Iowa: Clayton is a city in Clayton County, Iowa, United States. The population was 43 at the 2010 census, down from 55 at the 2000 census. Clayton is located directly on the Mississippi River and is only accessible by a very steep road. Many people have summer homes in Clayton due to its proximity to the Mississippi River.
Document 10: Aldi: Aldi launched in Great Britain, on 5 April 1990, when it opened its first store there in Stechford, Birmingham, using the wholly owned English registered company of Aldi Stores Limited and Aldi sales in Britain grew consistently. In October 2013, Aldi opened the 300th store in Great Britain. By 2017 Aldi had over 600 stores there, and was opening them at a rate of more than one a week with the aim of having a thousand stores by 2022.
Document 11: Everly, Iowa: Everly is a city in Clay County, Iowa, United States. The population was 603 in the 2010 census, a decline from 647 in the 2000 census. The Ocheyedan River flows to the south and west of the city.
Document 12: Karl Albrecht: Karl and Theo Albrecht were born and raised in a Catholic family in modest circumstances in Essen, Germany. Their father, Karl Sr, was employed as a miner and later as a baker's assistant. Their mother Anna, née Siepmann, had a small grocery store in the workers' quarter of Schonnebeck, a suburb of Essen. Theo completed an apprenticeship in his mother's store, while Karl worked in a delicatessen shop. Karl served in the Wehrmacht during World War II and was wounded on the Eastern Front. After the war, the brothers jointly took over their mother's business and founded Albrecht KG. They separated that company in 1961 into Aldi Nord, covering the part of Germany north of the Ruhr under Theo Albrecht, and Aldi Süd under Karl. The first Aldi (short for Albrecht Discount) was opened in 1962.
Document 13: Aldi: Country Name Aldi group Since Outlets Germany Aldi Nord 1961 2,339 Aldi Süd 1962 1,850 Australia Aldi Süd 457 Austria Hofer Süd 1968 430 Belgium Aldi Nord 1973 449 Denmark Aldi Nord 1977 220 France Aldi Marché Nord 899 Hungary Aldi Süd 2008 100 Ireland Aldi Süd 1999 111 Luxembourg Aldi Nord 1990 12 Netherlands Aldi Nord 498 Poland Aldi Nord 2008 113 Portugal Aldi Nord 2006 53 Slovenia Hofer Süd 2005 80 Spain Aldi Nord 2002 266 Switzerland Aldi Suisse Süd 2005 180 United Kingdom Aldi UK Süd 1990 726 United States Aldi US Süd 1976 1,600 Trader Joe's Nord 1979 418 total number of Aldi Nord stores 4,843 total number of Trader Joe's stores 418 total number of Aldi Süd stores 5,105 combined total of Aldi stores 10,366
Document 14: Aldi: In much of Australia, Aldi filled a void in the discount supermarket business that arose when the discount grocery chain Franklins went out of business. Aldi opened its first store in Sydney, 2001 and has grown rapidly since, maintaining a 12.6% market share as of early 2016.
Document 15: Trader Joe's: Trader Joe's Trader Joe's in Buffalo, New York Type Private Industry Retail (grocery) Founded 1958; 60 years ago (1958) (as Pronto Market) 1967 (1967) (as Trader Joe's) Pasadena, California, USA Founder Joe Coulombe Headquarters Monrovia, California, U.S. Number of locations 474 (as of 12 October 2017) Key people Dan Bane, Chairman & CEO Products Private label staple foods, organic foods and specialty products Revenue US $13 billion (2015) Number of employees 38,000 + Parent ALDI Nord Website traderjoes.com
ground_truth: Clayton County
sub_queries: where was the first aldi store in the us Answer: Iowa
Clayton, Iowa >> located in the administrative territorial entity Answer: Clayton County