Lincoln was born on January 24, 1733, in Hingham, Massachusetts to Colonel Benjamin Lincoln and Elizabeth Thazter. Lincoln's ancestors were among those who first settled in Hingham. In his early life, Lincoln worked on the family farm and did attend the local school, later in life though he felt the lack of further education and got a Masters degree at Harvard. In 1756, at the age of 23, Lincoln married Mary Cushing. They had eleven children.
He followed in his father's footsteps into local political office. At 21, Lincoln became the town constable and in 1755, Lincoln entered the 3rd Regiment of the Suffolk militia as an adjutant. In 1757, he was elected the town clerk of Hingham and was elected Justice of the Peace in 1762, also, in 1772, Lincoln was promoted to lieutenant colonel of the 3rd Regiment of the Suffolk militia. Being in the Suffolk militia allowed Lincoln to gain military experience which he used in three major battles of the American Revolution.
In 1776, he was promoted to brigadier general, then major general, then commander of all Massachusetts troops in the Boston area. After the British evacuation of Boston, Lincoln joined General George Washington at New York, commanding the right wing at the Battle of White Plains. Shortly after seeing action at Fort Independence, he was commissioned into the Continental Army as a major general.
In September of 1777, Lincoln joined Horatio Gates' camp near Saratoga to take part in the Battles of Saratoga but Lincoln did not play a big role in the Second Battle of Saratoga because he was wounded when a musket ball shattered his ankle and he was permenatly left with one leg shorter than the other.
After recovering from the severe wound, Lincoln was appointed Southern Department Commander in September 1778. Lincoln participated in the attack on Savannah, Georgia on October 9, 1779 and was forced to retreat to Charleston, South Carolina. Unluckily for Lincoln, he was beaten back to Charleston and was surrounded. Lincoln was forced to surrender to Lieutenant General Henry Clinton on May 12, 1780. This was one of the worst Continental defeats of the war. He was denied the honors of war in surrendering, which deeply rankled. Lincoln was exchanged as a prisoner of war, was paroled, and in the court of inquiry no charges were ever brought against him. After being exchanged, Lincoln soon returned to Washington's main army, even leading it south to Virginia and playing a major role in the Yorktown surrender on October 19, 1781. Cornwallis surrendered on October 19, 1781 according to some sources and October 20, 1781 according to others. General Lord Cornwallis was so humiliated by his defeat at the hands of the "Colonials" that he refused to personally surrender his sword to General George Washington, sending his second-in-command, General Charles O'Hara, in his stead. In response, General Washington sent his subordinate, Maj. Gen. Benjamin Lincoln, to accept Cornwallis's sword after the defeat at Yorktown.
One of the most important things Benjamin Lincoln did in his life time has to involve the ratification of the United States Constitution. In 1787, he was a member of the state convention that ratified the constitution. Also, earlier in 1787, Lincoln helped put an end to an uprising of farmers known as Shays' Rebellion. The uprising ended when the militia under Major General Benjamin Lincoln attacked the rebels and forced them to surrender in February.
He stayed active in public life in various capacities until his retirement in 1809. He died in Hingham on May 9, 1810.