Greene followed her husband, regardless of cold weather or illness in the camps, notably spending the winter at Valley Forge.

He was not repaid during his lifetime and through a chain of events the debt-ridden Greenes moved to Georgia to operate a rice plantation, relying on enslaved workers.

With the help of her friend Alexander Hamilton, arrangements were made with the federal government to repay the money that Nathanael spent to take care of his troops.

It enabled her, without apparent mental effort, to apply the instruction conveyed in the books she read, to the practical affairs of life".

[5] Catharine spent her early childhood years with her family on Block Island, where she learned to ride a horse at a young age.

[1] Beginning in 1772, Catharine was courted by Nathanael Greene, a fellow Rhode Islander, who was 12 years and six months her senior.

[2] After the initial Battles of Lexington and Concord of the American Revolutionary War (April 19, 1775 – September 3, 1783), Nathanael was made a brigadier general in the Continental Army and commander of Rhode Island's three regiments.

[11] Curious about the war, the pregnant Greene rode for a full day by horse and buggy from her home in Coventry to meet up with Nathanael at the American Army camp in Massachusetts.

[2] Greene formed a camaraderie with others her husband was stationed with, often the one responsible for planning social events for the troops to have respite.

[15] According to author Mary Ellen Snodgrass, "she kept up intense scrutiny of military politics" and corresponded with Thomas Jefferson, Alexander Hamilton, and Henry Knox, the secretary of war.

[13] Greene's lodging, 3 miles (4.8 km) from the main camp at Valley Forge, was used to entertain officers, including Jeremiah Wadsworth and Anthony Wayne.

Facing a long journey along rutted roads and several nights in shabby inns along the way, she climbed in her carriage with her son and traveled from Coventry to Philadelphia to meet her husband.

[19]When Nathanael was encamped at Morristown, New Jersey, Greene stayed a year with the family of William Alexander, Lord Stirling, on their estate in Basking Ridge.

[21] In December 1781, Greene visited George and Martha Washington in Philadelphia, before meeting up with her husband in the south in April 1782.

[1] When the war ended, Greene looked forward to having Nathanael home to share in the responsibility of raising the children and handling business and household affairs.

"[37] With his return to the family as a whole, Nathanael became a light-hearted parental figure, helping to share the burden of raising children, without strict discipline.

[37] At the urging of a trusted adviser, Greene personally presented to the United States Congress a petition for indemnity to recover funds that Nathanael had paid to Charleston merchants.

Greene contacted all she knew who might be helpful and gained Alexander Hamilton's support to obtain the money from the government for the debt.

[2] After her husband's death, Greene met the pressures of rearing her children and handling Nathanael's devastated finances.

[3] Greene met a young man named Eli Whitney, who tutored her neighbor's children,[42] but soon lost interest in that occupation.

[3] In an 1883 article in The North American Review titled "Woman as Inventor", the early feminist and abolitionist Matilda Joslyn Gage claimed that Mrs. Greene suggested to Whitney the use of a brush-like component, which was instrumental in separating the seeds from the cotton.

[11][43] Gage provided no source for this claim, and to date there has been no independent verification of Greene's role in the invention of the gin.

Her daughter Cornelia Greene Skipwith Littlefield describes her mother's role in "perfecting" the cotton gin with Eli Whitney in a Century magazine article written by her granddaughter.

[46] After selling Mulberry Grove in 1798, Greene and Miller lived at Dungeness plantation on the southern end of Cumberland Island, on land that Nathanael was awarded.