On January 14, 1798, Eli Whitney Sr., having convinced the U.S. War Department that he could mass-produce interchangeable musket parts, was awarded a contract for 10,000 muskets following the "Charlesville" (French M1766) pattern, then also being copied at the newly opened Springfield Armory and most of the U.S. musket contractors. Whitney's 1798 contract muskets measure between 58.875" and 57.75" in overall length, with longer arms delivered earlier. The .69-caliber smoothbore barrels measure approximately 44", though most are shy of that length by anywhere from .0625" to a maximum of 1.25". Lockplates are flat with a beveled edge and marked "U.STATES" in a curve on the pointed tail, with a perched eagle with down folded wings over "NEW HAVEN" forward of the cock. Four differences in material and manner of attachment of the pan distinguish subtypes: first delivery of 500 muskets in September, 1801 had an integral faceted iron pan (Type I); second delivery of 500 muskets in June, 1802 also had faceted iron pans, but were detachable (Type II); 1,000 muskets delivered in September, 1802 and March, 1803 had faceted detachable pans, but these were made of brass instead of iron (Type III); final 8,000 muskets delivered between 1803 and 1809, had detachable brass pans with a rounded bottom that Whitney copied from French M1777 musket (Type IV) and a rounded cock, also copied from French M1777 musket. Generally speaking, due to the limited production of Types I - III, they should command a higher price; prices are given for the more common Type IV 1798 contract musket. It should be noted however, that about 1804 Whitney delivered 112 Type IV muskets to Connecticut's "1st Company of Governor's Foot Guards". Although similar to Type IV musket, these 112 arms are distinguished by the absence of "U.STATES" on the tail of the lock and addition of the name "CONNECTICUT" to left sideplate. Such an arm should demand a considerable premium over usual Type IV musket.