Editing Allentown, Pennsylvania (section)

===20th century===
In 1905, Jack and Gus Mack moved [[Mack Trucks]], their motor company, from [[Brooklyn]] to Allentown, taking over the foundries of Weaver-Hirsh on S. 10th Street. By 1914, Mack Trucks developed a global reputation for manufacturing sturdy and reliable trucks and vehicles. Many were sent to [[Western Front (World War I)|Western Front]] battlefields in France just before the [[American entry into World War I|U.S. entered]] [[World War I]] in April 1917. The [[British Army]] nicknamed [[Mack AC]]'s five and seven-ton trucks the "Bulldog", which was later adopted as the company's corporate brand. Throughout the 20th century, Mack Trucks grew substantially, ultimately including eight Allentown-based manufacturing plants.<ref name="bicen"/><ref name="LCHS1"/>

In the early 20th century, largely as a result of Pennsylvania missionaries, Christians from [[Wadi al-Nasara]] in [[Syria]] began settling in Allentown. Syrian Christians ultimately developed a significant presence in the city, based largely in Allentown's Sixth Ward.<ref>{{cite book |last1=Richardson |first1=E. Allen |title=Strangers in This Land: Religion, Pluralism and the American Dream |date=2010 |publisher=McFarland |location=Jefferson, North Carolina and London |isbn=978-0-7864-3539-5 |page=18 |edition=Revised |url=https://books.google.com/books?id=-TiNAgAAQBAJ}}</ref> As of 2015, there were an estimated 5,200 [[Syrian Americans]] in Allentown and surrounding Lehigh Valley cities and towns.<ref>{{cite news |title=U.S. In America's Little Syria, a divide on accepting refugees |url=https://www.cbsnews.com/news/syria-refugees-syrians-allentown-pennsylvania-americas-little-syria/ |access-date=4 November 2024 |work=CBS |agency=Associated Press |date=20 November 2015}}</ref> 

Like several other regions in Pennsylvania, [[Pennsylvania Dutch language|Pennsylvania German]]-speaking residents existed in Allentown into the early 20th century. [[American Guide Series|Pennsylvania Guide]], compiled during the [[Great Depression in the United States|Great Depression]] by the [[Federal Writers' Project|Writers' Project]] of the [[Works Progress Administration]], described the impact of the [[Pennsylvania Dutch]] on Allentown's linguistic landscape, reporting in 1940 that:<ref>{{Cite book |title=Pennsylvania: A Guide to the Keystone State |last=Federal Writers' Project |date=1940 |publisher=Oxford University Press |edition=1st |page=182 |location=New York}}</ref>{{Blockquote
|text=Allentown is among the few large Pennsylvania cities where newspapers still carry columns written in the dialect. Although English predominates on the streets, there is a tendency to enunciate the 'v' with open lips, to soften the hard 'g' into 'ch,' and to use too frequently such words as 'already,' 'yet,' and 'once.' Here also are heard such colloquialisms as 'the pie is all,' (all gone) and 'it wonders (mystifies) me.'
|author=[[Federal Writers' Project]]|title="Part II: Cities and Towns"  |source=''Pennsylvania: A Guide to the Keystone State'' (1940)}}

In October 1945, following the end of [[World War II]], [[Western Electric]] opened a plant on Union Boulevard in Allentown. Six years later, in October 1951, the company manufactured and released the world's first [[transistor]], produced at the Allentown-based plant, and the Allentown-based company emerged as a leader in the nation's [[Aftermath of World War II|post-war]] electronics revolution.<ref>{{cite web |url=http://articles.mcall.com/1995-10-08/business/3069670_1_new-location-western-s-electric-s-50th-full-story |title=At&t Decided To Bring High Tech 50 Years Ago |website=mcall.com |access-date=October 23, 2017 |archive-date=November 17, 2015 |archive-url=https://web.archive.org/web/20151117013920/http://articles.mcall.com/1995-10-08/business/3069670_1_new-location-western-s-electric-s-50th-full-story |url-status=dead}}</ref> 

By the mid-20th century, Allentown was a major retailing and entertainment center distinct and separate from [[Philadelphia]] and [[New York City]]. Hess's, Leh's, and Zollinger department stores led to retail sector growth in the city, and dozens of smaller retail stores, restaurants, hotels, banks, and professional offices emerged in present-day [[Center City Allentown|Center City]], which was then referred to as downtown Allentown. At least seven cinemas and stage theaters were developed on Hamilton Street between 5th and 10th streets.<ref name="bicen"/><ref name="LCHS1"/>

====Deindustrialization and Rust Belt====
{{Further|Deindustrialization|Rust Belt}}
[[File:1974 - Hamilton Mall Postcard.jpg|thumb|A 1974 postcard of Hamilton Mall in [[Center City Allentown|Center City]], an ultimately failed attempt to redevelop Allentown's central business district as residents began fleeing the city for its suburbs in the 1970s]]
[[File:2018 - Center Square - Looking Northeast - 12 Oct - Allentown PA.jpg|thumb|The entrance to [[PPL Center]] (on left) in Center City in October 2018]]
By the mid-1960s, Allentown's economy was booming for decades, but the city's rising taxes and regulations prohibited the city's expansion, leading many Allentown residents, especially those from the post-[[World War II]] [[baby boomers|baby boom generation]], to flee Allentown for its suburbs. [[Salisbury Township, Lehigh County, Pennsylvania|Salisbury]], [[South Whitehall Township, Pennsylvania|South Whitehall]], and [[Whitehall Township, Pennsylvania|Whitehall]] townships each had large areas of farmland, which were prime locations for residential real estate development. A significant portion of Allentown's [[working class]] began migrating to the newer and more affordable housing developments in these suburbs, which offered lower taxes, more green space, less crime, and newer schools.

Throughout the late 20th century, the departure of Allentown residents for its suburbs began representing a major challenge to the city's government and [[Allentown School District|school district]], both of which began experiencing significantly diminished resources. Allentown School District's financial challenges, in turn, further increased working class flight to the city's suburbs, creating a sea change in the city's demographics. With the departure of many working class families from older [[Center City Allentown|Center City]] [[List of Allentown neighborhoods|neighborhoods]], many of the city's homes were sold to landlords who converted them into inexpensive multifamily apartments, a considerable portion of which were transformed into [[Section 8 (housing)|government-subsidized housing projects]], which was then permitted under the city's lax zoning and city codes.

With Allentown's neighborhoods and school system declining, the city focused on attempting to develop its [[Hamilton Street]] retail district, largely ignoring Allentown neighborhoods not located in Center City. This, in turn, further increased the flight of Allentown residents to the city's suburbs, leading to the development of a growing number of suburban shopping centers and services, which were built to accommodate these expanding suburban communities. In 1966, [[Whitehall Mall]], the first closed shopping mall north of Philadelphia, opened in Whitehall Township. Ten years later, in 1976, [[Lehigh Valley Mall]], a second suburban closed mall even larger than Whitehall Mall, opened north of [[U.S. Route 22 in Pennsylvania|U.S. Route 22]] in [[Fullerton, Pennsylvania|Fullerton]]. Stores in Allentown's downtown shopping district began closing, replaced with stores whose customers were less affluent and large downtown areas that were razed and replaced with parking lots. In an attempt to compete with fast-growing and newer suburban shopping areas, the downtown Allentown business district was rebuilt with a multiblock row of stores known as Hamilton Mall, featuring newly covered sidewalks and managed traffic patterns. The city's economic plight began being citing as a prominent example of a [[Rust Belt]] city. In 1982, [[Billy Joel]] released the single "[[Allentown (song)|Allentown]]", the lead song on ''[[The Nylon Curtain]]'' album, which addressed the city's economic plight in the late 20th century.

The effort to rebuild the downtown shopping district ultimately proved unsuccessful, and two of the city's major department stores, Leh's and Zollingers, closed by 1990. The third, [[Hess's]], was sold to [[The Bon-Ton]] in 1994, which closed its Hamilton Mall location two years later, in 1996.<ref>{{cite web |url=http://www.allentownpa.gov/Play/History |title=History |website=allentownpa.gov |access-date=October 23, 2017 |archive-date=October 24, 2017 |archive-url=https://web.archive.org/web/20171024154418/https://www.allentownpa.gov/Play/History |url-status=dead}}</ref> In 1993, Corporate Center, the city's new flagship business center on N. 7th Street, fell victim to a large [[sinkhole]], leading to its condemnation and ultimate demolition. Combined with challenges confronting Center City, Allentown also was heavily impacted by a significant downturn in manufacturing throughout the [[Northeastern United States|U.S. Northeast]], which began undergoing and suffering from [[deindustrialization]], a product of foreign competition, trade policies, and relatively higher U.S.-based manufacturing costs. Many Allentown factories and corporations began closing or relocating.