[9] However, maps from the 1860s erroneously depict the village of Ojibway at the mouth of the Ripple River.

Due to the importance of regional trade at Lexington, the route of the Northern Pacific Railroad was planned to pass near there.

Aitkin was founded in 1870 when the Northern Pacific Railroad was extended to that point, replacing and annexing Lexington.

[10] The city and county were named for William Alexander Aitken, a partner of the American Fur Company and chief factor of the company's regional operations in the early 19th century.

In the late 19th and early 20th century, a massive wave of immigrants, mostly from present-day Ireland, Germany, and Scandinavian countries, moved into the Aitkin area to work in the logging and riverboat industries.

After the Great Depression and World War II, the logging industry declined.

The area developed as a farming community, based on production of cattle and poultry, which continued until the late 1970s to early 1980s.

By the 1990s, Aitkin had changed again, developing as a community for retirement and tourism, especially with its lake areas.

Health care, education, human services, and non-profit organizations are some of the major contributors to the modern-day Aitkin economy, along with the hospitality industry.

[14] According to the United States Census Bureau, the city has a total area of 2.20 square miles (5.70 km2), all land.

43.5% of all households were made up of individuals, and 25.1% had someone living alone who was 65 years of age or older.

46.5% of all households were made up of individuals, and 30.2% had someone living alone who was 65 years of age or older.