Question: What city located in Lehigh County, Pennsylvania, was home to the business empire of Henry Clay Trexler?

Context paragraphs:
Trexler Nature Preserve: The Trexler Nature Preserve is an 1,108 acre county park owned and maintained by Lehigh County, Commonwealth of Pennsylvania.  The preserve is situated in Lowhill Township and North Whitehall Township and the land that comprises the preserve was originally purchased between 1901 and 1911 by local industrialist General Harry Clay Trexler.

Lynn Township, Lehigh County, Pennsylvania: Lynn Township is a township in Lehigh County, Pennsylvania, in the United States.  It is a suburb of Allentown, Pennsylvania, in the Lehigh Valley region of the state.  The largest township by area in Lehigh County, it is the most rural and least densely populated township in the county.

Carbon Lehigh Intermediate Unit: Carbon Lehigh Intermediate Unit #21 (CLIU), located in Schnecksville, Pennsylvania, Lehigh County USA, is one of twenty nine Intermediate Unit Educational Service Agencies created by an Act of the General Assembly of Pennsylvania in 1971.  CLIU provides services to 14 public school districts, non-public schools in its service region and two Vocational-Technical schools in Carbon County and Lehigh County.  The agency has no taxing power.  Its revenues come come: federal grants, state grants, private grants, annual payments from each public school district in its region and charges to individuals for some services like driver's education.  The agency provides many services including specialized special education services and training for teachers to meet their state mandated continuing professional education with some offered online.  CLIU21 also operates a Librarians' Consortium for librarians from public libraries, private libraries, school libraries and higher education librarians.

Coplay Cement Company Kilns: Coplay Cement Company Kilns, also known as the Saylor Park Industrial Museum, is an open-air historic site located at Coplay, Lehigh County, Pennsylvania.  The nine kilns were built in 1892-1893, and used for the production of Portland cement.  They are constructed of locally produced red brick, and are known as Schoefer vertical kilns.  They were shut down in 1904.  The Coplay Cement Company donated the kilns and surrounding land to Lehigh County in 1975, for a cement industry museum.  It is operated as a partnership between the County of Lehigh, which owns and maintains the site, and the Lehigh County Historical Society, which provides educational services.  It was added to the National Register of Historic Places in 1980.

Harry Clay Trexler: Henry Clay Trexler (April 17, 1854 – November 17, 1933) was an American industrialist who built a business empire in Allentown, Pennsylvania.

Lehigh County Historical Society: Lehigh County Historical Society is a nonprofit organization, founded in 1904, dedicated to collecting, preserving, and exhibiting the history of Lehigh County, Pennsylvania and the Lehigh Valley.  The Historical Society and Lehigh Valley Heritage Museum are located at 432 West Walnut Street in Allentown.

Pennsylvania Route 873: Pennsylvania Route 873 (PA 873) is a north-south, two-lane road mainly located in northern Lehigh County, Pennsylvania with a small section in Northampton County.  Its southern terminus is at PA 309 in Schnecksville.  Its northern terminus is at PA 248 in the Lehigh Township hamlet of Weiders Crossing.  The route runs through rural areas in northern Lehigh County, intersecting the western terminus of PA 329 in Neffs.  PA 873 passes through Slatington as Main Street before it crosses the Lehigh River into Northampton County and immediately reaches its northern terminus south of Lehigh Gap in Blue Mountain.

Ricketts, Pennsylvania: Ricketts is a ghost town that was established as a lumber mill company town in Sullivan and Wyoming counties, in the U.S. state of Pennsylvania.  Ricketts was built in 1890 along Mehoopany Creek in both Colley Township in Sullivan County and Forkston Township in Wyoming County for sawmills of the Trexler and Turrell Lumber Company.  It was named for Robert Bruce Ricketts, who owned most of the land and timber around the village, and who was a partner in the company with Harry Clay Trexler, J.H. Turrell, and others.  Ricketts had 800 inhabitants at its peak and extended into the northernmost section of what is now Ricketts Glen State Park.  Rail lines were built to the mills at Ricketts, including the Bowman Creek branch of the Lehigh Valley Railroad which opened in 1893.  The mills closed in 1913 when the lumber was exhausted and the last house was torn down in the 1930s.

Trexler Historic District: Trexler Historic District, also known as Trexler Station, is a national historic district located in Albany Township, Berks County, Pennsylvania.  The district encompasses 15 contributing buildings in the village of Trexler.  It is a collection of homes and commercial buildings erected between 1790 and 1930.  Notable buildings include the 3-story, log Georgian style Ritter House (1790); Amos Trexler House (1886); 1 1/2-story log house (c. 1800); Trexler General Store (1890); cider mill (c. 1850); 3-story, frame storage building (1917); and Nathan Trexler House (1875).  The Ritter House one housed an inn and tavern known as the Washington Inn.  Also in the district is the separately listed Bridge in Albany Township.

Allentown, Pennsylvania: Allentown (Pennsylvania Dutch: "Allenschteddel") is a city located in Lehigh County, Pennsylvania, United States.  It is Pennsylvania's third most populous city and the 224th largest city in the United States.  As of the 2010 census, the city had a total population of 118,032 and is currently the fastest growing city in all of Pennsylvania.  It is the largest city in the metropolitan area known as the Lehigh Valley, which had a population of 821,623 residents as of 2010 .  Allentown constitutes a portion of the New York City Combined Statistical Area and is the county seat of Lehigh County.  In 2012, the city celebrated the 250th anniversary of its founding in 1762.

Supporting paragraphs: Harry Clay Trexler Allentown, Pennsylvania
Answer: Allentown, Pennsylvania