[6][7][8] Before European settlers came to inhabit the Quad Cities, the confluence of rivers had attracted many varying cultures of indigenous peoples, who used the waterways and riverbanks for their settlements for thousands of years.

At the time of European encounter, it was a home and principal trading place of the Sauk and Fox tribes of Native Americans.

The treaty resulted in the Native Americans ceding 6 million acres (24,000 km2) of land to the United States in exchange for a much smaller reservation elsewhere.

As demand for river-based transportation increased along the upper Mississippi, the navigability of the river throughout the "Rock Island Rapids" became a greater concern.

Boat crews needed rest areas to stop before encountering the rapids, places to hire expert pilots such as Phillip Suiter, who was the first licensed pilot on the upper Mississippi River, to guide the boat through the rocky waters, or, when the water was low, places where goods could be removed and transported by wagon on land past the rapids.

As the Industrial Revolution developed in the United States, many enterprising industrialists looked to the Mississippi River as a promising source of power generation.

The combination of energy and easy access to river transportation attracted entrepreneurs and industrialists to the Quad Cities for development.

[10] It was built by the Rock Island Railroad Company and replaced the slow seasonal ferry service and winter ice bridges as the primary modes of transportation across the river.

The Rock Island Railroad Company selected Abraham Lincoln as their trial lawyer and won after he took the case to the US Supreme Court.

The river towns that were thoughtfully planned and competently led flourished, while other settlements, usually get-rich-quick schemes for speculators, failed to pan out.

But with the growth of Rock Island County, during the 1930s the term "Quad Cities" came into vogue, as East Moline was given "equal status".

Despite the fact that the region had earned the name "Quad Cities", the National Basketball Association had a franchise in Moline, Illinois, from 1946 to 1951 called the "Tri-Cities Blackhawks".

[13] Beginning in the late 1970s, economic conditions caused major industrial restructuring, which disrupted the basis of the region's economy.

Factories which closed included International Harvester (Navistar) in Rock Island and Case IH in Bettendorf.

Examples of revitalization and rebirth include: Over the years, several communities in the Quad Cities region have proposed or performed mergers.

[28] The predominant ethnicities in the Quad Cities are of northern European descent, including German, Irish, and English, as well Scandinavian (Mostly Swedish and Norwegian) and Dutch.

Since 1916, the region has supported the Quad City Symphony Orchestra, which presents a year-round schedule of concerts at the Adler Theatre in Davenport and Centennial Hall in Rock Island.

The Handel Oratorio Society, dating to 1880, is the second-oldest organization of its kind in the nation and presents annual performances of "Messiah" along with another major work for choir and orchestra.

The Quad Cities' three traditional community theaters – Playcrafters Barn Theatre (founded in 1920, comedies and dramas)[41] and Quad City Music Guild (1948, musicals) in Moline, and Genesius guild (1957, outdoor Shakespeare and Greek comedies and tragedies) in Rock Island – were joined in 1976 by Circa '21 Dinner Playhouse, a professional dinner theater in downtown Rock Island's historic Fort Theatre.

In 2012, the Mississippi Valley Fair that is held in Davenport served as the film location for Rodney Atkins' music video "Just Wanna Rock N' Roll".

Also in 2012, the PBS Frontline documentary Poor Kids was filmed in and around the Quad Cities showing poverty from a child's perspective.

A total of five bridges accessible by automobiles connect Iowa with Illinois in the Quad Cities across the Mississippi River.

The Fred Schwengel Memorial Bridge carries Interstate 80 and connects Le Claire, Iowa, with Rapids City, Illinois.

In 2008, United States Senators Tom Harkin, Chuck Grassley, Dick Durbin, and Barack Obama sent a letter to Amtrak asking them to begin plans to bring rail service to the Quad Cities.

[47] In October 2010, a $230 million federal fund was announced that will bring Amtrak service to the Quad Cities, with a new line running from Moline to Chicago.

[49][50] The multi-modal Moline Q Station building was completed in early 2018, with the attached Westin Element hotel opening in February.

The Tri-Cities Blackhawks, named in honor of the Sauk war chief Black Hawk, was the next top-level professional sports franchise.

Vibrant Arena at The MARK occasionally hosts NCAA Division I college basketball conference tournaments as well as NBA and NHL exhibitions.

The Quad Cities has hosted minor league baseball teams since the Davenport Brown Stockings first played in 1878.

It has drawn dozens of top PGA players over the years, including Tiger Woods, Vijay Singh, and Payne Stewart.