Greene was born the son of a Quaker farmer and smith. He was born at Potowomut, in the township of Warwick, Rhode Island. Though his father's sect discouraged "literary accomplishments", he acquired a large amount of general information, and made a special study of mathematics, history and law. At Coventry, Rhode Island, whither he removed in 1770 to take charge of a forge built by his father and his uncles, he was the first to urge the establishment of a public school; and in the same year he was chosen a member of the legislature of Rhode Island, to which he was re-elected in 1771, 1772 and 1775. He sympathized strongly with the Whig, or Patriot, element among the colonists, and in 1774 joined the local militia. At this time, he began to study the art of war. In December 1774 he was on a committee appointed by the assembly to revise the militia laws. His zeal in attending to military duty led to his expulsion from the Society of Friends.
In 1775, in command of the contingent raised by Rhode Island, Greene joined the American forces at Cambridge, and on June 22, he was appointed a brigadier by Congress. To him, Gen. George Washington assigned the command of the city of Boston after it was evacuated by Gen. Sir William Howe in March 1776. Greene's letters of October 1775 and January 1776 to Samuel Ward, then a delegate from Rhode Island to the Continental Congress, favored a declaration of independence.
On August 9, 1776, Greene was promoted to be one of the 4 new major-generals and was put in command of the Continental troops on Long Island. He chose the place for fortifications and built the redoubts and entrenchments of Fort Greene on Brooklyn Heights. Severe illness prevented his taking part in the battle of Long Island. He was prominent among those who advised a retreat from New York and the burning of the city, so that the British might not use it. Greene was placed in command of Fort Lee, and on October 25, he succeeded Maj. Gen. Israel Putnam in command of Fort Washington. He received orders from Washington to defend Fort Washington to the last extremity, and on October 11, Congress had passed a resolution to the same effect; but later Washington wrote to him to use his own discretion. Greene ordered Col. Magaw, who was in immediate command, to defend the place until he should hear from him again, and reinforced it to meet Howe's attack. Nevertheless, the blame for the losses of Fort Washington and Fort Lee was put upon Greene, but apparently without his losing the confidence of Washington, who indeed himself assumed the responsibility.
At Trenton, Greene commanded one of the 2 American columns, his own, accompanied by Washington, arriving first; and after the victory here he urged Washington to push on immediately to Princeton, but was overruled by a council of war. At the Brandywine Greene commanded the reserve. At Germantown, Greene's command, having a greater distance to march than the right wing under Sullivan, failed to arrive in good time--a failure which Greene himself thought would cost him Washington's regard; on this, with the affair of Fort Washington, Bancroft based his unfavourable estimate of Greene's ability. But on their arrival, Greene and his troops distinguished themselves greatly.
At the urgent request of Washington, on March 2, 1778, at Valley Forge, Greene accepted the office of quartermaster-general, and of his conduct in this difficult work, which Washington heartily approved, a modern critic, Col. H. B. Carrington, has said that it was "as good as was possible under the circumstances of that fluctuating uncertain force." He had become quartermaster-general on the understanding, however, that he should retain the right to command troops in the field; thus we find him at the head of the right wing at Monmouth on June 28. In August, he and Lafayette commanded the land forces sent to Rhode Island to co-operate with the French Adm. d'Estaing, in an expedition which proved abortive.
In June 1780, Greene commanded in a skirmish at Springfield, New Jersey. In August he resigned the office of quartermaster-general, after a long and bitter struggle with Congress over the interference in army administration by the Treasury Board and by commissions appointed by Congress. Before his resignation became effective it fell to his lot to preside over the court which, on September 29, condemned Maj. John Andre to death.
On October 14, Greene succeeded Brig. Gen. Horatio Gates as commander-in chief of the Southern army, and took command at Charlotte, North Carolina on December 2. The army was weak and badly equipped and was opposed by a superior force under Gen. Charles Cornwallis. Greene decided to divide his own troops, thus forcing the division of the British as well, and creating the possibility of a strategic interplay of forces. This strategy led to General Daniel Morgan's victory of Cowpens (just over the South Carolina line) on January 17, 1781, and to the battle at Guilford Court House on March 15, in which after having weakened the British troops by continual movements, and drawn in reinforcements for his own army, Greene was defeated indeed, but only at such cost to the victor that Gen. Guy Tarleton called it "the pledge of ultimate defeat."
Three days after this battle, Cornwallis withdrew toward Wilmington. Greene's generalship and judgment were again conspicuously illustrated in the next few weeks, in which he allowed Cornwallis to march north to Virginia and himself turned swiftly to the reconquest of the inner country of South Carolina. This, in spite of a reverse sustained at Gen. Lord Francis Rawdon's hands at the Battle of Hobkirk's Hill on April 25, he achieved by the end of June, the British retiring to the coast. He then gave his forces a 6 weeks rest on the High Hills of the Santee, and on September 8, with 2,600 men, engaged the British under Lt. Col. James Stuart at the Battle of Eutaw Springs. The battle, although tactically drawn, so weakened the British that they withdrew to Charleston, where, Greene penned them during the remaining months of the war. Greene's Southern Campaign showed remarkable strategic features that remind one of those of Turenne, the commander whom he had taken as his model in his studies before the war. He excelled in dividing, eluding and tiring his opponent by long marches, and in actual conflict forcing him to pay for a temporary advantage a price that he could not afford. He was greatly assisted by able subordinates, including the Polish engineer, Tadeusz Kosciuszko, the brilliant cavalry captains, Henry ("Light-Horse Harry") Lee and William Washington, and the partisan leaders, Thomas Sumter and Francis Marion. South Carolina and Georgia voted Greene liberal grants of lands and money. The South Carolina estate, Boone's Barony, south of Edisto in Bamberg County, he sold to meet bills for the rations of his Southern army. On the Georgia estate, Mulberry Grove, he settled in 1785, after twice refusing (1781 and 1784) the post of Secretary of War, and there he died of sunstroke.
Greene was a singularly able, and -- like other prominent generals on the American side -- a self-trained soldier, and was second only to Washington among the officers of the American army in military ability. Like Washington he had the great gift of using small means to the utmost advantage. His attitude towards the Tories was humane and even kindly, and he generously defended Gates, who had repeatedly intrigued against him, when Gates's conduct of the campaign in the South was criticized.