On Thursday morning, April 20th 1775, Putnam and his son Daniel, who was then fifteen years of age, had gone into the field near the tavern at Brooklyn Green to plow. They were busy at work when about eight o'clock a messenger rode into the village in hot haste, with a dispatch for Daniel Tyler, Jr. It was from the town clerk of Worchester, Massactusetts, who had forwarded a copy of a letter which he had received from the Committee of Safety at Watertown, dated "Wednesday morning, Near 10 o'clock, April 19, 1775," announcing that the British had fired on the militia at Lexington, had "killed six men and wounded four others," and were on their march into the country. Young Tyler hurried with the news to his father-in-law in the field. In instant response to the alarm, Putnam - so wrote his son Daniel in after years - "loitered not but left me, the driver of his team, to unyoke it in the furrow, and not many days after to follow him to camp." Without changing his working clothers, the energetic patriot mounted a horse at the stable that he might himself spread the alarming tidings and also consult with the militia officers and the committees of the neighbouring towns of Windam County. He hastened to the home of Governor Jonathan Trumbull at Lebanon, and received orders from him to go to Boston.
Meanwhile, about three o'clock in the afternoon, another dispatch reached Putnam's village, giving an account of the fight at Concord. Colonel Ebenezer Williams of Pomfret, a member of the Connecticut Committee of Safety, forwarded the news by express to Canterbury and elsewhere, urging "every man who is fit and willing" to come out for action, for "there were about forty of our men killed" by the British.
When Putnam returned home, two hours or so after the second dispatch was received, he found hundreds of men gathered on Brooklyn Green ready to obey his orders. He told them that, according to the arrangements which he had been making on his consultatory tour, military officiers would soon arrive to direct their movements. It was now nearly sunset, but without stopping to rest or to change the checkered famer's frock which he had been wearing since he left his plough in the morning, Putnam, indefatigable patriot that he was, started on a night ride for Cambridge. That he reached there the next day, and after consultation with the Committee of Safety galloped on to Concord is evident from the letter which he wrote to Colonel Williams of Pomfret. He had ridden not less than a hundred miles in eighteen hours.