21-year-old Nathan Hale, perhaps America's best-known early spy, served with Knowlton's Rangers. In September 1776, Washington ordered Knowlton to send some of his men behind British lines in Long Island to reconnoiter enemy forces gathering to attack the Continental Army in Manhattan. After the Revolutionary War began in 1775, Hale joined a Connecticut militia unit and was elected first lieutenant within five months. His company participated in the Siege of Boston, but Hale remained behind. It has been suggested that he was unsure as to whether he wanted to fight, or possibly that he was hindered because his teaching contract in New London did not expire until several months later, in July 1775. On July 4, 1775, Hale received a letter from his classmate and friend Benjamin Tallmadge, who had gone to Boston to see the siege for himself. He wrote to Hale, "Was I in your condition, I think the more extensive service would be my choice. Our holy Religion, the honor of our God, a glorious country, & a happy constitution is what we have to defend." Tallmadge's letter was so inspiring that, several days later, Hale accepted a commission as first lieutenant in the 7th Connecticut Regiment under Colonel Charles Webb of Stamford.Hale was also a part of Knowlton's Rangers, the first organized intelligence service organization of the United States of America, led by Lieutenant Colonel Thomas Knowlton. In the spring of 1776, the Continental Army moved to Manhattan to defend New York City against the anticipated British attack. In August, the British soundly defeated the Continentals in the Battle of Long Island via a flanking move from Staten Island across Brooklyn. General George Washington was desperate to determine the location of the imminent British invasion of Manhattan; to that end, Washington called for a spy behind enemy lines, and Hale was the only volunteer.