Some time back I complied a spreadsheet to break-out the pace of Federal cannon production. It was not a perfectly scientific survey, as I worked off the date of credit on published ordnance returns. As published sources offer slightly different numbers, I opted to work strictly from those offered in the appendices in The Big Guns: Civil War Siege, Seacoast and Naval Cannon, by Edwin Olmstead, Wayne E. Stark, and Spencer C. Tucker. The authors of that work proved a full listing of both heavy and field weapons.
Keep in mind that a gun was generally only “credited” after it had undergone proofing and received acceptance marks. While not in every single case a consistent reference point, the crediting date is at least a benchmark for metrics.
Consider this subset of data, focused on the three main weapons (the “big three”) used by the Federal armies – 10-pdr Parrotts, 3-inch Ordnance Rifles, and 12-pdr Napoleon Guns.
I’ve broken down the “credited” numbers by quarter, for each type, looking at the war years (1861-65). Several points to ponder.
First, based off the credit dates, Parrott production peaked early and then tapered off to nothing by mid-war. When production of the 3-inch model started, production figures are practically a “bell curve,” and peaked again at the end of 1864.
The credit numbers for the 3-inch Ordnance Rifles likely are skewed. With such a high figure credited at the end of 1861 and start of 1862, I wonder if these were production batches held up waiting acceptance trials. Perhaps the Ordnance Department was not quite sure about wrought iron and held up the official credits.
Credits of the 3-inch Ordnance Rifles slacked in the middle of 1863. Did the Confederate invasion have any influence on this? Perhaps contradicting this premise, production again slacked at the end of 1864. But note the last credits for the rifles came well after Appomattox.
Napoleon credits had two distinct surges. Numbers reached three figures across 2nd, 3rd, and 4th quarters of 1862. After falling off through 1863, credits reached record numbers in the last quarter of that year and remained high in the first quarter of 1864. While one might like to correlate those numbers to the pace of the war, nothing conclusively matches up.
Napoleon production ceased entirely after the middle of 1864. Did the army have plenty of Napoleons at that point?
I’d added a column to indicate the quarterly totals for the “big three.” The raw credit numbers show an early war surge, with that late war “bulge” clearly influenced by Napoleon deliveries over the winter of 1863-4. And high production of 3-inch Ordnance Rifles in the 2nd quarter of 1864 kept those numbers to three figures.
The furthest right column increments the quarterly figures to show the total number of the “big three” credited and, by assumption, delivered, by that time in the war. For instance, by the 2rd quarter of 1862, the Ordnance Department had credited 912 of the “big three.” During the fighting in September 1862, the Federals brought 323 cannons of all types on the Maryland Campaign. Assuming the 24 batteries in the field at Perryville, Kentucky had six guns each, that added 144 cannons. Hard to tally complete numbers for the forces along the Mississippi, but I’d guess roughly another 24 or 25 field batteries, and add 160 or so more cannons. For the three main areas of operation, the Federals needed about 920 to 925 cannons.
So in theory, if the logistic system functioned responsively, and issue was conducted with a minimal amount of bureaucracy, ALL batteries in the field during the important battles of August-October that year would have Parrotts, Ordnance Rifles, or Napoleons. Of course, that assumes a lot of good effort from the supply system. It also leaves out the substantial quantities of cannons lost to the Confederates, and thus pointed back at the Federals on those same fields.
Production numbers and the supply system caught up to demand by 1863. As any student of Gettysburg knows, all but a handful of Federal batteries used the “big three” during that battle. However, the Army of the Cumberland hauled quite a number of old 6-pdr guns and 12-pdr howitzers into North Georgia later that summer. Tallies for batteries at Vicksburg and Port Hudson are somewhat skewed due to the use of heavy weapons for siege operations there.
I’d advance the notion that the Federal army needed no more than 1300 field pieces to fill its wartime needs. By the end of 1862, the northern factories had produced enough “new” weapons to meet that need. Due to attrition, battlefield losses, and other factors production lines remained open. But regardless, the Yankee war machine produced enough field cannons to arm its army and for good measure, the opposing side!