R. A. Gould, the Actuary of the U. S. Sanitary Commission, wrote in the introduction to this report,
On taking charge of the Statistical Department of the United States Sanitary Commission, in August, 1864, it was found that considerable progress had been made in collecting the ages of the soldiers of our volunteer regiments. … Tables have thus been formed for twenty-seven States, Territories, or geographical groups, exhibiting the number of men at each year of age in the volunteer organizations, at the time of their muster into the service of the United States.
This historic government report represents a unique application of statistics to the U. S. military during the Civil War. The report contains heavy mathematics in its discussion of the methodologies used to collect and analyze data on U. S. soldiers, but the conclusions should be able to be understood by most genealogists.
One very interesting revelation in the report comes in the discussion of enlisted men below and above the legal military age (defined in 1862 as between the ages of 18 and 45). Table I, “Classified Summary of Enlisted Volunteers,” notes that 113 infantry soldiers reported their age at last birthday as just 13 years of age! The numbers double (or more) for each year of age up through 17. Perhaps less astonishing, but still worthy of note, 1,942 infantry men were aged 50 years and over.
The statistical analysis is not limited to the sole purpose of compiling the ages of soldiers, however. These numbers are also compared to statistics provided by the 1860 federal census. The author of the report believed that the ages of enlisted men provided significant insight into the populations from which these enlistees originated.
The report does not provide any names of individual soldiers, so some genealogists may overlook this source. This would be a mistake. The Civil War affected nearly every family in the country at least peripherally. This statistical report provides little-known data about those who served in the U. S. Army in general, and applies the data to society at large. Those with a background in statistics may find more value in the report, but even those with no such understanding can benefit from the report’s conclusions.
Explore “Ages of U. S. Volunteer Soldiery” at http://purl.org/net/nysl/nysdocs/NY005904085
This resource is one of over 9000 listed in version 3.0 of Online State Resources for Genealogy. To purchase the ebook, visit http://haitfamilyresearch.com/onlineStates.htm.
 U. S. Sanitary Commission Statistical Bureau, Ages of U. S. Volunteer Soldiery (New York, 1866), 1; digital images, New York State Library (http://purl.org/net/nysl/nysdocs/NY005904085 : accessed 7 December 2013).
 The Statutes at Large, Treaties, and Proclamations, of the United States of America …, volume 12 (Boston: Little, Brown & Co., 1863), 597, chapter 201, “An Act to amend the Act calling forth the Militia to execute the Laws of the Union, suppress Insurrections, and repel Invasions, approved February twenty-eight, , and the Acts amendatory thereof, and for other Purposes.”
 Ages of U. S. Volunteer Soldiery, 5.