Before the arrival of the mostly Anglo-Americans in the 19th century, this area was long occupied by the Illinois Confederation, a loose grouping of up to 12 to 15 Native American tribes.

[5] After trading, warfare and other encounters with French traders, who entered this area before the Anglo-Americans, their numbers declined.

In large part that was due to the high mortality from new infectious diseases, which adversely affected Native Americans across the continent.

The area that developed as Belvidere was first permanently settled by European Americans in 1835: Simon P. Doty and Daniel Hilton Whitney.

[7] Major industries developed along the river and railroad, including the National Sewing Machine Company, which operated here from 1886 to the 1940s.

In 1906, former female sheriff Sarah Ames moved to South Dakota; she named the area where she settled after her home town.

[9] In 2007 a statue was erected in front of Belvidere High School in memorial of the lives lost.

To this date, the Belvidere tornado remains the sixth worst weather disaster to happen at an American school.

[10] On December 7, 2009 an explosion occurred at an NDK America building, when a large pressure vessel ruptured during a crystal-growing process.

The CSB found that stress corrosion cracking had occurred, unnoticed, in one of the crystal-growing autoclaves, leading to the catastrophic failure.

They also found that NDK management had been warned multiple times over the years that the dangerous levels of hot sodium hydroxide inside the vessels would corrode the steel walls.

However, NDK management insisted buildup of byproducts from the crystal-growing process would form a protective layer against the corrosion.

Furthermore, during the factory's construction, the local government had been made aware that NDK's crystal-growing vessels were in violation of several state codes; when confronted, NDK had persuaded them to grant a special exception, and to hitherto allow them to conduct their own onsite inspections without outside interference.

However, the vessel that ruptured had never been internally inspected to test the "byproduct buildup" theory, during its many years of service.

After a smaller leak occurred in January 2007, NDK was warned about safety concerns again, this time by insurance investigators, who were ultimately ignored.

Finally, the CSB determined the method for growing crystals used at NDK's Belvidere facility was prohibitively dangerous in the first place, pointing out such methods had been already abandoned by other crystal-growing facilities in favor of safer, lower-pressure and lower temperature processes.

[24] As part of the settlement of the 2023 United Auto Workers strike, Stellantis agreed to reopen the plant in 2025, to construct a mid-size Ram pickup.

[25][26][27] Dean Foods and General Mills operate manufacturing plants on the bank of the Kishwaukee River.

General Mills recently announced a large expansion in the area, soon to begin construction on a 1.3 million square foot distribution center in a newly annexed southwestern portion of the city.

"Project Yukon" is a recently announced Cold Storage facility, which will be over 1.2 million square feet on 200 acres in the Southwest side of the city.

This is expected to bring up to 700 jobs, ground is expected to be broken mid-2023 Pettit Memorial Chapel, designed by Frank Lloyd Wright; the Lampert-Wildflower House, and the Belvidere Post Office, designed by James Knox Taylor, are listed on the National Register of Historic Places.

[29] Belvedere is served by the old Chicago & North Western line to Rockford (present day Union Pacific).