In December 1775, British Colonel William Faucitt and Hessian minister Martin Ernst von Schlieffen drafted a treaty promising the Hessian Landgraf Friedrich II a large sum of money in return for soldiers. The British had spent the fall of 1775 offering subsidies to German states of the Holy Roman Empire they were allied with in return for manpower. The Germans who “were used to being sent outside their own country to server under foreign flags” were happy to oblige. Many Germans were eager to fight in America. When the treaties were finished and the call to arms went out across the German states, many men, especially from the State of Hessen-Kassel, volunteered. Those already conscripted did not complain much when they received word of their expedition to the colonies. This is because the Germans had an “unfriendly disposition toward a people who rebelled against their rightful king,” and were perfectly content with getting paid to fight such an enemy.
The treaty with the German state of Hessen-Kassel was signed on January 15, 1776, and promised 12,000 men to the service of King George III of England. Hessen-Kassel provided the British fifteen regiments of infantry, each with five companies of men, four grenadier battalions and two companies of Jäger (known as chasseurs or sharpshooters in English). The Jäger in particular were in high demand. Jäger, a German word that translates to “hunter” and can be used as both a singular and plural word, were recruited from huntsmen and foresters who were skilled in the use of rifled weapons normally used to hunt boar. They were skilled shots, self-sufficient in battle, and swift, able to efficiently load and fire a rifle, a skill which took greater dexterity than firing the muskets of the day. Most importantly, they were valiant. Though the Jäger did not play a pivotal role in the American Revolution and suffered from the defeats of their regular counterparts, the actions of the Hessian Jägerkorps as a whole positively contributed to the British war effort. This was especially true in the campaigns in New York in 1776 and Pennsylvania in 1777.
The Jäger differed in appearance from other Hessian troops, wearing a green jacket with crimson facings instead of the blue jackets of Hessian infantrymen. A Jäger company consisted of four commissioned officers, 16 non-commissioned ones, one non-combat officer, and 105 men. Unlike the disciplined line of a foot or grenadier regiment, the Jäger fought in a more scattered skirmish formation. Because of this, the Jäger had to be “good shots, agile, intelligent, and self-reliant.” This self-reliance allowed a member of the Jägerkorps the freedom to make decisions on his own during a skirmish, or during battle. Jäger were considered partisan troops. The duty of partisan troops was “to keep the enemy from his own main force…” This was a duty that Jäger would accomplish many times during the early parts of the American Revolution.
The most prominent difference between Jäger and regular infantry was the use of a rifle. Jäger were expected to be proficient in the use of a rifled weapon. The Jäger rifle was much shorter than an infantry musket, and instead of a smooth bore a rifle barrel was grooved, giving the bullet spin as it exited the barrel. The spin gave the rifle greater accuracy, making it an ideal weapon for sharpshooters who wished to keep their distance from their opponents. The rifled grooves made it significantly more difficult to ram the bullet down the barrel, making the rate of fire much slower than a musket in an age where rate of fire could turn the tide of battle. The long loading time paid off when it came to firing, which could be done accurately up to 400 yard s away from the enemy.
The first division of 8,000 Hessians, with one of the two Jäger companies, set off for America on May 6, 1776 and arrived at Staten Island in early August. General Howe had waited for the Hessian forces to arrive before launching his attack on New York City. Historian Rodney Atwood states that Howe did this because the British knew they could not subdue the American rebels without the help of the German. Atwood says, “without them [the Hessians] the subjugation of the rebels would be unthinkable.” Along with a longer loading time, another downside was that a rifle could not carry a bayonet. This left the Jäger vulnerable to being attacked by an enemy who charged with bayonet or cavalry looking to take advantage of the Jäger skirmish formation. To counter this, Jäger would often advance with grenadiers. Captain Johann Ewald, a company commander in the Jägerkorps who later wrote extensively about military theory, would mix Jäger with regular troops, so the latter could provide cover to the former.  This tactic proved especially useful during the crossing of the Schuytlkill River in 1777. Jäger under Captain Werden and Lorey and a battalion of Hessian grenadiers were able to quickly cross the river and secure its fords. This move assisted British General Sir William Howe in capturing Philadelphia.
The first action the Hessian Jägerkorps saw was on Long Island, at the village of Flatbush, New York, where the Jäger, along with other Hessians, had stationed themselves on August 22. The Jägerkorps had been placed with the brigade under the command of Colonel Carl von Donop, and were led by Captain August von Wreden. Wreden would distinguish himself throughout the war, eventually earning, along with four other Jäger officers, the order Pour la Vertu Militaire, a prestigious award of Hessen-Kassel.
The fight at Flatbush began the following day when three hundred American riflemen under Colonel Edward Hand began a skirmish with the Hessians. The previous day, the Americans had withdrawn from the Hessian advance and took position in the wood that lay ahead of the village, giving them an advantageous position to skirmish with the Germans. An observer, Johann Heinrich von Bardeleben, from the Donop regiment, which was stationed near the village, wrote a marginal note in his diary: “As the enemy had a detachment in the woods in our front, they attacked single outposts, from that place.” Several houses and crops were burned by the Americans, but after a day and a night of skirmishing, the Americans only succeeded in wounded twelve men and killing one Jäger. The Jäger clearly showed they were comfortable with this type of fighting, proving their effectiveness as a skirmishing force. Captain Max O’Reilly of the Block Grenadier Battalion described how the Jäger “crept about through the fields like Croats on their bellies.” There is no mention of how many men the Americans under Hand lost, but it can be assumed it was enough to make Colonel Hand reconsider his position. Hand eventually withdrew from outside the village when the grenadiers brought their cannons forward and the Jäger advanced quickly while the Americans were cannonaded.