Between 1838 and 1840, the undeclared Aroostook War flared between the United States and Canada, and the Battle of Caribou occurred in December 1838.

Caribou was the "jumping off" point for a large influx of settlers who immigrated directly from Sweden in 1870–1871, and settled the nearby "Swedish colony."

The small town grew throughout the late 19th century, and with the coming of the Bangor and Aroostook Railroad in the 1890s, agricultural exports exploded.

It provided a major economic boost to the area, with construction starting in 1947 on "Limestone Army Air Field."

Caribou was incorporated as a city in 1967 on February 23, but the area's boom period leveled off in the 1970s as a result of difficulties in its traditional potato industry.

In September 1984, Caribou was the lift-off location of the first successful solo balloon crossing of the Atlantic Ocean by Colonel Joseph Kittinger.

This flight is memorialized at the Rosie O'Grady Balloon of Peace Park one mile (1.6 km) south of the city on Main Street.

Designed in the Romanesque Revival style by local architect Schuyler C. Page, it was built in 1911–1912 with a $10,000 grant.

Caribou is located in the geographical center of Aroostook County, at an elevation of 449 feet (137 m) above sea level.

In sparsely populated Aroostook County, Caribou is at the hub of spokes serving the area via U.S. 1 and Maine State routes 89, 161, 164, 205 and 228.

Daily flights are scheduled to and from northern Maine on jetBlue with connections to Boston Logan International Airport.

The closest deep-water port is Rivière-du-Loup, Quebec, 120 miles (190 km) north of Caribou, on the St. Lawrence River.

Given the city's economic and cultural ties with the Canadian provinces of Quebec and New Brunswick, cross-border partnerships and relationships are often a common facet in many businesses.

Caribou has a humid continental climate (Köppen Dfb), with very cold, snowy winters, and mild to warm summers, and is located in USDA hardiness zone 4b/4a.

Services provided are fire prevention, suppression, medical emergency response, Critical Care Air and Ground transfers, Local and Long Distant transfers from one health care facility to another, high angle and low angle rescues, HAZ-MAT, vehicle extrication, and health education.

In Caribou and throughout Aroostook County, the two major agricultural crops are potatoes at one point peas and broccoli.

Farm implement sales and services and the development of several area processing plants are examples of the influence agriculture has on the local economy.

Caribou is served by WAGM-TV, a CBS affiliate located in Presque Isle, which is the only full-power commercial television station north of Bangor.

Residents of Caribou receive the Maine Public Broadcasting Network, a PBS affiliate, over WMEM-TV, as well as the CBC from Canada.

In addition, listeners can receive other radio stations in northern Maine, Western New Brunswick and Eastern Quebec.

The Caribou Performing Arts Center draws acts and shows from all over the United States and Canada.

Caribou is also home to Echoes magazine, a quarterly publication about rural culture and heritage focused primarily on northern Maine.

Caribou has over a dozen cross-country ski trails with varied scenery and terrain within a one-hour drive of the city.

Other recreational options include a nine-hole golf course, multi-use hiking/biking/ATV trails, a four screen movie theater, a frisbee golf course, a roller skating rink, Spud Speedway (the area's only race track), a bowling alley, The Maine Dance Academy, and several excellent parks.

Goughan's Berry Farm includes miniature golf, a petting zoo, a carousel, ice cream, and a corn maze in the fall.

The community completed construction of a new outdoor tennis complex in 2009, to complement the existing courts at Teague Park.