Shortly before the war broke out, the U.S. Army adopted a plan to convert M1841 6-pounder field guns from smoothbore to rifled artillery.

There were two major types produced, both were bronze with a bore (caliber) of 3.8 in (97 mm) that would accommodate ammunition designed by Charles Tillinghast James.

Charles Tillinghast James invented cotton-mill machinery, then was elected Senator from Rhode Island in 1851–1857.

He subsequently became a militia major general from Rhode Island and began creating projectiles suitable for rifled artillery.

[1] On 1 November 1860 a U.S. Army board recommended that half of the existing smoothbore cannons in forts and arsenals should be rifled according to the plan of General James.

On 15 December 1860, General James signed a contract that required him to rifle half of the cannons at United States arsenals and forts.

[1] Late in 1861, the Ames Company received an order to produce several 6-pounder smoothbore guns and 3.8-inch rifles.

[8] The bronze pieces called Type 1 all have the external appearance of a Model 1841 6-pounder field gun, 3.8 in (97 mm) caliber, 15-groove rifling of right-hand twist, and a weight of about 880 lb (399.2 kg).

However, Henry Larcom Abbot published test ranges that were compiled by A. P. Rockwell of the 1st Connecticut Light Artillery Battery.

[13] Hazlett, Olmstead, and Parks tentatively identify a Type 3 14-pounder James rifle that was made of cast steel.

There are three painted steel 3.8-inch rifled guns at Shiloh National Military Park that appear to match the purchase order.

Every single type and series of James rifle listed above can be found at Shiloh National Military Park.

[8] The guns achieved great accuracy when test fired, but the bronze rifling degraded fairly quickly.

[18] At the Battle of Pea Ridge on 7–8 March 1862, Louis Hoffman's 4th Ohio Battery was armed with what is described as four 12-pounder James rifles and two M1841 12-pounder howitzers.

[19] The 4th Ohio Battery took part in Franz Sigel's highly successful artillery bombardment on the second day.

[20] Another source specifically stated that the 4th Ohio Battery was, in fact, armed with four 3.8-inch James rifles as late as the third quarter of 1863.

[21] At the Battle of Antietam on 17 September 1862, the 1st Ohio Battery commanded by Captain James R. McMullin was attached to the Kanawha Division in the Union IX Corps.

We know that the battery was armed with six 14-pounder James rifles because McMullin specifically referred to 3.800 inch guns in his after action report.

[25] A few weeks later at the Battle of Perryville on 8 October 1862, the Union Army of the Ohio used 23 14-pounder James rifles out of a total of 147 guns.

[27] By the time of the Battle of Gettysburg was fought in the east on 1–3 July 1863, the Army of the Potomac employed only four James rifles.

[27] Cogswell's Battery Illinois Light Artillery was armed with four 3.8-inch James rifles as late as August 1864 when the unit garrisoned Nashville, Tennessee.

After opening fire again, John McArthur's infantry division attacked and achieved a decisive break in the Confederate defenses.