Newell Green (N.G.) Larimore was born August 29, 1835, in Bourbon County, Kentucky. He grew up on a farm near St. Louis, Missouri, and graduated from Wymans High School in St. Louis.

He married Susan Ashbrook on September 2, 1855. They had two sons: Walter and Clay. Susan Larimore died in July 1862. Larimore remarried five years later to Mollie E. Jameson, and had two more children: a son, Jameson, and a daughter, Cora.

At the end of the Civil War, Larimore became a prominent business leader in St. Louis, starting up the St. Louis Warehouse Company and the Central Elevator Company. It was said that the first telephone lines in St. Louis were built to connect the Central Elevator Company's office with three of its elevators. Larimore also served one term on the St. Louis City Council.

In 1880, Larimore organized the Elk Valley Farming Company, which farmed more than 15,000 acres in rural Grand Forks County, beginning in 1881. The nearby city of Larimore was named in his honor that same year. The Elk Valley Farming Company proved to be one of the largest and most successful farming operations in the United States.

Larimore was a well-known member of the Democratic Party, and in 1893 declined an offer to run for governor of North Dakota. He served as president of the North Dakota Chautauqua Association for eight years, and served one year as president of the Board of Regents of the University of North Dakota. He also was a regent of the Methodist University in Wahpeton, and a trustee of Wesley College at the University of North Dakota from 1895 until his death in 1913.

Although Larimore spent most of the later years of his life in North Dakota, he died in St. Louis in November 1913.