The military hanger is a short (approximately 25 inches) single-edged cutting sword. Because the sword is short, it was commonly used by infantrymen to complement the musket. But advances in bayonet technology began to render the hanger obsolete.
In 1768 a British Royal Warrant decreed that only sergeants, grenadier companies, fifers and drummers, and Royal Highlanders would carry the hanger. Similarly, France eliminated the hanger from infantry use in 1764 except for sergeants and grenadiers. The same situation presented itself in the Continental Army during the Revolutionary War when the hanger was only used by non-commissioned officers.
An interesting note about military hangers is the diversity of their styles. This is because sword specifications of the era mandated a length but little else.