It was Horace Greeley, editor of the New York Tribune, who popularized the phrase, "Go West young man, go West," but it was his visionary agricultural editor, Nathan C. Meeker, who spearheaded one of the most successful colonization experiments ever attempted in the "Great American Desert."

Meeker called for ambitious individuals with high moral standards and money to form a colony based upon the following principles: cooperation, irrigation, agriculture, temperance, religion and education. The call elicited 3,000 responses and 59 individuals who ultimately formed a joint stock company called Union Colony in December 1869.

On October 12 of the following year, Horace Greeley paid his one and only visit to the town that bore his name. By that time, colonists had erected houses on town lots close to the confluence of the South Platte and Cache la Poudre rivers, etablished a newspaper, built irrigation canals and designed streets to be 100 feet wide and ultimately lined with beautiful trees.

A reading room opened in 1870 followed by the first school in 1872, a courthouse in 1883 and a college in 1889. Greeley's concern for the financial well being of the community led him to require the original settlers to be solid enough to allow the community a good start. This foresight helped the city of Greeley to become successful when other similar ventures failed.