Previously organized as a city and later as a borough, Willimantic is currently one of two tax districts within the Town of Windham.

It is home to Eastern Connecticut State University and the Windham Textile and History Museum.

The word was first attested in English writing as Waramanticut in 1684,[9] and later as Wallamanticuk, Wewemantic and Weammantuck before being standardized as Willimantic.

It is commonly translated as "land of the swift running water", but the word more likely means "place near the evergreen swamp".

Up to the outbreak of World War II, it continued to be a center for the production of silk and cotton thread.

[7] The city was a major rail hub; in the early twentieth century, as many as a hundred trains ran through Willimantic daily.

[17] But hard times followed; American Thread moved to North Carolina in 1985[18] and without it, the town's economy foundered.

[23] The coverage upset local residents, and the state appointed a task force to study the issue.

Later, Estonian, Ukrainian, Latvian, Lithuanian, and Puerto Rican immigrants moved to the town in search of mill jobs.

[2] Willimantic's first factory was built in 1822 on Main Street by Charles Lee, followed by the first of the Jillson Mills in 1824.

The Jillson Mills were bought in 1854 by a group of investors from Hartford, who formed the Willimantic Linen Company.

In 1879, the Company built a woodworking factory to source its spools in Howard, Maine, which was renamed Willimantic in 1881.

4, the first industrial building designed for electric lighting and the world's largest cotton mill at the time,[14] which stood until it was burned down by two teenagers in 1995.

[18] Major employers include Willimantic Waste Paper Company, which specializes in the collection and recycling of fiber products, scrap metal, and co-mingled plastic refuse,[34] as well as Brand-Rex Corporation, which maintains a manufacturing making specialty wire and cable for commercial and industrial customers.

[35] In January 2018, a fire destroyed the Willimantic Waste Paper processing plant, however it was rebuilt and is currently operating.

The Connecticut Eastern Railroad Museum, located where the Columbia Junction Freight Yard was, has a collection of locomotives and rolling stock, as well as a reconstructed six-stall roundhouse.

The event is run by Willimantic Renaissance, a local nonprofit organization, and draws about eight thousand attendees.

Middle-school students can also apply for admission by lottery to the Charles H. Barrows STEM Academy in Windham.

Notably, the only connections to the outside world are via surface roads, as the Willimantic Bypass is only divided between its two intersections with Route 66.

In the 1960s, Interstate 84 was intended to connect Willimantic to Hartford in the west and Providence in the east, but the plan was eventually abandoned.

[65] Though the city was a major rail hub, Interstate 84 only skirted the area between 1970 and 1983, until plans to continue the highway eastward were scrapped by 1984, after which time U.S. 6 was moved to the Willimatic Bypass.

[68] At its peak, the passenger rail system ran forty trains a day through Willimantic.

[69] The NH operated the Nutmeg and several unnamed local trains on an east–west route from Waterbury, through Hartford and Willimantic, and on east to Boston.

Eastern Connecticut State University also broadcasts WECS, the local NPR affiliate, on FM 90.1.

[86] In Marvel Comics "Avengers: Celestial Quest", Mantis recounts raising her son, Sequoia, in Willimantic for a year.