It was a sweltering afternoon in New Jersey: jungle-hot, tropically humid, dripping, draining, the kind of day that wrings you out and leaves you lying there gasping in the shade. Few who pass through bustling, industrial modern-day Newark think the Garden State lives up to its nickname, let alone merits rain forest status. But on the long, oppressive afternoon of June 28, 1778, it did.It was definitely the wrong day for a battle, especially for groups of cursing, sweating men wearing wool uniforms and packed shoulder to shoulder into firing lines three rows deep. The red-coated British Regulars and blue-coated American Continentals fought each other in a sprawling, bloody clash well beyond the cooling tree groves and out in the sun-drenched farm fields of Monmouth, N.J., on the hottest day of the year. To keep going on a day like that, soldiers need water—lots of it. Rudyard Kipling summarized it superbly in his well-known poem, “Gunga Din”: “But when it comes to slaughter/You will do your work on water/An’ you’ll lick the bloomin’ boots of ‘im that’s got it.” It is unknown if any boots got licked at Monmouth, but those with water found no shortage of takers. The trick involved finding the givers.American supply arrangements were sketchy in 1778. The Continental Army included a Quartermaster Corps. Indeed, that vital group had existed since June 16, 1775, two days after the formation of the Army itself. Undermanned, underfunded and decidedly overworked, the quartermasters depended on civilian contractors. These hired helpers tended to depart quickly at the first shot. On the broiling Monmouth battlefield, resupply came thanks to soldiers detailed from the fighting regiments.The 4th Pennsylvania Artillery’s guns anchored an essential ridge at the north end of the Continental line. Enemy cannon balls bounded up the slope, bowling over some Americans unable to scramble out of the way. A half-mile away, British Regulars, led by the famed 42nd Regiment of Foot (The Black Watch), formed for another assault. Debilitated by the blazing sun and fierce fighting, both sides were nearing the end of their strength. In this heat, one more good push by either opponent might finish the day. The cry arose from the Continental ranks: “Water! Bring us water!”By ones and twos, soldiers left the busy cannon crews and headed to nearby McGellaird’s Brook to fetch water. Among those hefting wood buckets was at least one woman, not in uniform but very much “on the strength,” as they said at the time. Like many young wives, Mary Ludwig Hays, the 24-year-old spouse of an artilleryman, had been with the battery since the grim winter at Valley Forge. Hays and the other wives washed laundry, cooked, and helped tend the sick and wounded. Most of the women stayed at Valley Forge when the Continentals marched east to fight at Monmouth, but Hays went with the Army. With British musket balls sighing overhead and hostile cannon shots sizzling through the hot grass, Hays carried two sloshing water buckets up to her husband and the rest of the embattled artillerymen. The men drank some but used most of the precious liquid to swab and cool the scorching metal gun barrels. When the British regiments surged forward again, the cannons needed to be ready to reply.That British attack began sooner than any of the Pennsylvania gunners expected. The experienced British commanders massed a grand battery of 16 pieces. Determined to break the American line, the British artillery opened fire in unison. Like the other American batteries, the 4th Pennsylvania Artillery replied. A furious artillery duel ensued. Water resupply stopped as every soldier turned to serve the guns.Choking clouds of dark gray smoke billowed in the still air. In the fetid gloom, the crews executed the well-known drill. After each shot, a rammer pushed a long pole with a sponge into the barrel, extinguishing powder sparks. Sponging the barrel; lugging heavy cannon balls; poking, prodding and shoving the next powder bag and iron shot down the throat; and shifting the heavy carriage to align with a target glimpsed through stifling smoke—it could wear down even stout artillerists on a cool day. On a scorcher like this one, men wobbled and collapsed. Hays’ husband was among them. The relentless British fire accounted for some, but the merciless sun certainly got more.Hays stepped into the gap. She had evidently learned the loading and firing drill taught at Valley Forge. Without missing a beat, she kept swabbing out the shimmering-hot barrel, twisting the long sponge rod with cool skill. Another artilleryman watched a British cannonball skip up the low ridge and cross between the woman’s legs, shredding her lower skirt and petticoat. “Well,” she remarked, “that could have been worse.” Thanks to Hays’ work and that of hundreds of other Continental Artillery and Infantry troops, the British never mounted that final push. Rather, as the sun finally sank into the west, they pulled back. The Continental Army held the field.In the aftermath of the Battle of Monmouth, several American participants remarked on the brave performance of the female water bearer who became a gunner at the height of the engagement. Few knew her name, though. Stories circulated among the soldiers about a woman they called Molly Pitcher and SGT Molly. When word reached GEN George Washington, he determined Hays’ real name and then issued her a formal warrant as a noncommissioned officer. She became SGT Mary Hays.After the war, like so many veterans then and now, Hays rejoined the civilian community. She had a son, and after her husband died in 1786, she married a fellow Revolutionary War veteran, John McCauley. The state of Pennsylvania eventually granted her a military pension, acknowledging “services rendered.” After her death in 1832, she was buried in the cemetery in Carlisle, Pa., not far from the present home of the U.S. Army War College. In 1916, a statue was placed near her grave, depicting Mary Ludwig Hays McCauley wielding a ramrod. The carving includes her nickname: “Molly Pitcher.”At the time, and ever since, many have made much of the novelty of a female artillerist. Soldiers know better. The other American gunners at the Battle of Monmouth cared about only two things, the same two points on which they judged every soldier: Did Hays know what to do? Would she fight? When she answered yes to both, and did so bravely, her gender ceased to be an issue for her side and became a problem for the enemy. That, in the end, is the purpose of every soldier.Those fond of raising the debate about the role of women in combat would do well to look to our country’s history. American women have participated in every one of this country’s wars, great and small. There have been political arguments and legal wrangling as to when, where and in what capacity women could serve, but they have served every time, always pushing the envelope, consistently doing more than asked. It has not been easy. Out where people are shooting at each other, there is seldom a surplus of volunteers. In combat, soldiers are grateful for those who are willing to pull their own weight.Hays made her name in the Revolutionary War, as did Margaret Corbin, who also served in another battle. In the Civil War, Mary Edwards Walker was appointed an assistant surgeon of the 52nd Ohio Infantry Regiment. She earned the Medal of Honor at the urging of GEN William Tecumseh Sherman, a hard-bitten commander notoriously stingy with praise. The Army and Navy nurses captured on Bataan and Corregidor in 1942 all earned the Bronze Star for their heroic service in combat and in brutal Japanese prison camps; the senior Army nurse, MAJ Maude C. Davison, received the Distinguished Service Medal for her extraordinary leadership. In the recent Iraq campaign, SGT Leigh Ann Hester was awarded the Silver Star for her role in a firefight with insurgents southeast of Baghdad in 2005. Many women have received other valor awards, Purple Hearts and Combat Action Badges in the fighting since September 11, 2001. Unshackled by recent regulatory changes, female soldiers have contributed plenty in this hard war. There will be more to come.Wiser heads predicted as much, some since the days of Molly Pitcher herself. In 1982, U.S. Air Force Maj. Gen. Jeanne M. Holm wrote a prescient book titled Women in the Military: An Unfinished Revolution. Holm began her service in World War II and rose to be the first American woman promoted to two-star rank. She believed that females could—and should—serve in every role in the U.S. military.We are nearly there. It took a while, but the revolution that began one hot afternoon in 1778 is nearing its end. Somewhere out there, SGT Molly is smiling.