Caldwell is the county seat of Noble County, Ohio. Residents named the town after Joseph and Samuel Caldwell, who were the original owners of the land. While Caldwell was not formally established until 1857, numerous people resided in the area as early as 1814.
Caldwell grew slowly. In 1880, only 602 people inhabited the town. Over the next decade, the population more than doubled to 1,248 people. This growth was primarily due to the increasing need for oil as the United States became more industrialized. During the early nineteenth century, local residents were drilling for salt to preserve their food, as well as for other uses. Unfortunately, for the workers, they struck oil instead. They had no idea of oil's eventual importance to the United States economy. Because of this first well, drilled in 1814 on the outskirts of modern-day Caldwell, Noble County claims to be the site of the first oil well in the United States.
Thanks to oil's increasing importance, Caldwell prospered during the last two decades of the nineteenth century. In 1886, the town boasted four newspaper offices, three churches, and one bank. This same year, numerous manufacturing businesses existed in Caldwell, including the town's largest employer, the Caldwell Woollen Mills, which employed twenty-five workers making blankets and other wool products. Other local businesses produced flour, hosiery, doors, clothing, and flooring.
Caldwell's economic fortunes declined in the first part of the twentieth century, as Noble County's oil reserves became depleted. Today, most residents find employment in retail stores or in health care. Caldwell had only 1,956 residents in 2000. Over one-half of the town's residents were school-aged children in 2000. Caldwell's nearly two thousand residents comprised almost one-seventh of Noble County's entire population, making the county one of the least populated in Ohio.