The 1st United States Sharpshooters were an infantry regiment that served in the Union Army during the American Civil War. The volunteer recruits had to pass a rifle test in order to qualify to be a member of the Sharpshooters; each man had to be able to place ten shots in a circle of 10 inches (250 mm) in diameter from 200 yards (180 m) away. They were able to choose a rifle and position of their preference for the test. A man eligible to be a Sharpshooter had to possess a keen eye, steady hands and a great deal of training and skill with a rifle. In addition to that, for a man to be a Sharpshooter, it took cool nerves in order to be able to estimate carefully their target, determine the high trajectory needed and to take in consideration the effect that any current wind may have.