The Model 1840 Noncommissioned Officers' Sword was based on a German version of the infantry sword used by British troops during the Napoleonic Wars. In August of 1840, the United States Army Ordnance Department contracted with Schnitzler & Kirschbaum ( S&K )of Solingen, Prussia for 1000 swords of this pattern. Later, N.P. Ames Manufacturing Company of Cabotville received their first contract in 1844 to make this sword, followed by Ames Manufacturing Company of Cabotville (1847), then by Ames Manufacturing Company of Chicoppee , Mass in the 1850s. 

The Model 1840 Army NCO sword was worn and saw frontline service by American sergeants during such great conflicts as the Mexican-American War (1846 - 1848), the Civil War (1861 - 1865), and the Spanish American War (1898). A shorter version with a 26 inch blade (the typical 1840 Army NCO sword sports a 31 inch blade) was carried by musicians, and thus was called the Model 1840 Musician's sword. NCO's of shorter stature and cadets also carried this variant. Other ranks allowed to carry it included Sergeant Major, Quartermaster, Ordnance Sergeant, Hospital Steward, Corporal and Pioneer (Combat Engineer). 

Many of the Model 1840 Army NCO swords manufactured by the primary contractor, the Ames Manufacturing Company, were very badly manufactured with a blunt edge, but they still proved effective in combat, as the sword could be used like an iron club to break bones. The 1840 Army NCO sword was the main weapon of standard bearers and hospital stewards, as well as a secondary weapon for infantry NCO's. The sword was also used by the Confederates who captured many after seizing state arsenals. 

The M1840 (1840 Army NCO sword) has had a long service life. In 1868 the United States Army ordnance board recommended that no more leather sword or bayonet scabbards be purchased. (the sword was originally was equipped with a leather scabbard), so after the leather ones were used up, a black Japanned steel scabbard was substituted along with a new pattern leather frog. The 1840 Army NCO sword remained in service as a ceremonial weapon until general orders No. 77 dated August 6, 1875 discontinued its use. A modern version of this sword with steel scabbard is currently permitted for wear by US Army platoon sergeants and first sergeants (Army Field Manual FM 3-21.5) and is mostly used during a regimental CSM (Sergeant Major or SGM) change of command as a symbolic transfer of authority between CSM's.