A Comparison of Numerical Strengths
It is possible to construct an approximate picture of the relative strengths of the two armies at Richmond and Petersburg, using information available in several volumes of the Official Records. The table below summarizes what can be found there.
The Federal forces were almost entirely from two organizations, the Army of the Potomac (under Meade) and the Army of the James (under Butler and then Ord). At the end of the siege, when Sheridan returned from the Shenandoah Valley, his cavalry was usually considered as a separate command.
The Confederate forces were mostly from the Army of Northern Virginia, commanded by Robert E. Lee. There was also the Department of Richmond, commanded by Richard S. Ewell, and the Department of North Carolina and Southern Virginia, in which the Petersburg defense troops were placed.
Strength tables in the Official Records give several different numbers. There is the "aggregate present," the "aggregate present and absent," the "present for duty, equipped," and the "effective total present." Usually the last two categories are the most meaningful measure of the numerical strength that can be put into battle. Even this is an over-estimate, as all regiments would go into battle with some of their present-for-duty strength assigned elsewhere. The Confederates tended to be more efficient than the Yankees in this regard, so the figures reported here are 93% of the Confederate "present for duty, equipped" and 85% of the corresponding Federal figure. These multipliers are based on empirical evidence comparing the number of muskets actually taken into battle with formal strength returns.
An additional complication is that separate commands often reported on different dates. When possible, the figures below are all based on "end-of-the-month" dates, but occasionally it was necessary to combine Confederate figures for early in the month with figures for the end of the month, simply because orderly, complete, data was not available. And, it should be said, no data at all was available for the Confederate forces at the end of March, 1865.
|June, 1864||96,076||55,350||1.74 - 1|
|July, 1864||89,049||57,528||1.55 - 1|
|August, 1864||51,142||48,501||1.05 - 1|
|September, 1864||71,504||45,563||1.57 - 1|
|October, 1864||77,302||54,651||1.41 - 1|
|November, 1864||81,922||58,287||1.41 - 1|
|December, 1864||95,131||59,171||1.61 - 1|
|January, 1865||100,429||45,829||2.19 - 1|
|February, 1865||106,286||47,197||2.25 - 1|
|Average||86,603||52,453||1.65 - 1|