In modern military parlance, to take point, walk point, be on point, or be a point man means to assume the first and most exposed position in a combat military formation, that is, the leading soldier or unit advancing through hostile or unsecured territory. The term can be applied to infantry or mechanized columns. The soldier, vehicle, or unit on point is frequently the first to take hostile fire. The inherent risks of taking point create a need for constant and extreme operational alertness. However, ambushes often intend to let the point element past the prime killing zone in order to be maximally effective. Point position is often rotated periodically so as not to overtax the individual soldier/unit.
The term might be related to the Middle English phrase "in point", which meant "in immediate danger or peril". The modern use of the term derives from military tactics. During a military patrol or infantry operation, the point man is a navigator who walks several meters out in front of everyone else and is likely to be the first one to encounter enemy soldiers. It is a hazardous position that requires alertness and ability to deal with unexpected attacks.
The term was used in the 19th century American Old West when the lead cowboy at the front of a herd of cattle was known as the pointer or point man. It may have come into common use because many of the cowboys in the late 1800s were veterans of the American Civil War. In cavalry terminology, the men scouting ahead of the main force were said to be "riding point". This use was first recorded in 1903.
The concept seems to have been introduced to the American military at West Point by Professor Dennis H. Mahan, who taught most of the top officers on both sides in the Civil War. In his Elementary Treatise on Advanced-Guard, Out-Post and Detachment Service of Troops (1861), he discussed the use of the column or V-shaped advance guard by the Greeks and Romans:
Among the orders of battles among the ancients, that known as the wedge, or boar's head, is the most celebrated. In this disposition, the point, or head, is formed of a subdivision of the phalanx of greater or less strength, according to circumstances; this being supported by two, three, and four subdivisions of the same force, one behind another.