Nellie Cline was born on 4 December 1863, in Matteson Township, Branch County, Michigan. She was one of two children born to parents John and Elizabeth Coward (née Benton). Shortly after her birth, her husband was drafted to fight in the Civil War. As a young child, her family moved to Sherwood, where she was raised in a Methodist household.

After graduating from high school at the age of 18, she married Almus Bert Cline on 4 October 1881, who was aged 20 at the time. She and her husband then began farming on her parents’ homestead, which they would do together for over 70 years. The couple had four children: three sons Ivan, John, and Almus, as well as a daughter named Mildred who died young. Her husband worked as the sheriff of Branch County from 1918-1924. He chose his wife to work by his side, making her Branch County’s first female deputy sheriff. She wore a gun and a badge, just like her husband, and also had an interest in politics.

In 1951, she and her husband celebrated their 70^th wedding anniversary, making them the longest-married couple in the state of Michigan. Bert died in 1953 at the age of 91, following close to 72 years of marriage. Following her husband’s death, she began living with her son, John, who was her only surviving child. At the age of 97, she suffered a fall and broke her hip, but was still able to walk with the aid of a walker until she was around 105. In June 1970, at the age of 106, she moved into the Maple Lawn Medical Care Facility in Coldwater, and spent most of her day in bed, with her blindness mostly preventing her from doing many of her favorite hobbies like reading, sewing, and crocheting. Her health would eventually improve somewhat, and by the time she was 111, she preferred to be out of her bed, doing activities from her wheelchair.

Nellie Cline died in Coldwater, Michigan, USA, on 9 February 1975, at the age of 111 years, 67 days. She was survived by her son, four grandchildren, nine great-grandchildren, and 17 great-great-grandchildren.