Military Organization of the Union Army
( Or what is a Brigade, Regiment, or a Corps?)
Well established standards were used in the Union Army to create military units. What is interesting is how these standards were applied to volunteers and their recruitment. The Union army was very small in April of 1861. When Fort Sumter was fired upon by the CSA the Union needed men -- and fast! Lincoln had little in resources. The Federal Government had only a fraction of the power it has today. The president had little choice but to place an emergency call for troops -- but not to the Army or the Navy. The plea was made to the Governors of each state. Wisconsin's Governor was Alexander Randall -- for whom Camp Randall in Madison, Wisconsin is named. Lincoln called for 75,000 men on April 15th, 1861. Randall received a request for only one regiment from Wisconsin. A regiment was approximately 1000 men and officers. These men were to serve for 90 days. It's incredible to think, with our benefit of hindsight, that it was believed that the Union would need only 75,000 men for 90 days!
Many Wisconsin boys responded to the call and the quota was exceeded by the 16th, forming the 1st Regiment of Wisconsin Volunteers. Some of the men who came too late stayed in camp and were formed into other Wisconsin Regiments. Those turned away soon had opportunity to join units as it became obvious that more men would be needed. Soon the call for "three year" volunteers would be heard.
Want to be an Officer of Volunteers? Lets say you were a prominent (and well-to-do) citizen of your county. Perhaps you were an attorney or a public official or had military experience. To become an officer of Volunteers you just needed to raise a company. You might use your influence (and money) to gather about 100 or so men (or boys who might pass for men) from your county who wanted to volunteer. This was relatively easy to do at the beginning of the war when the fervor of fighting for the Union was high. Once you had a good number of men you would gather them together in one spot and have them sign up. Next you would hold an election. Because you organized (and sometimes even equipped and paid for) the unit you would most likely be elected Captain. Some of your friends may have brought a number of men along to help fill out the company. So another election for Lieutenant would follow. Your friend might then be Lieutenant. Elections might then follow for 2nd Lieutenant, 1st Sergeant, 2nd to 5th sergeants and corporals. Sometimes military experience would get you an officers position, but many times no experience was needed at all.
Other men were needed beyond the members listed above to fill out your company. Even Musicians and a Wagoner were required. Governor Randall spelled out the exact composition in a proclamation. On August 20, 1861 the Governor called for more men. Each Company coming in to Camp Randall had to have the following...
1 Captain, 1 First Lieutenant, 1 Second Lieutenant, 1 First Sergeant, 4 other Sergeants (2nd-5th), 8 Corporals, 2 Musicians, 1 Wagoner, and from 64 to 82 Privates.
This made the minimum size of a company to be allowed to come into camp to be 83 men. The largest allowed was 101 men. A company which came in "light" might be made to wait until further volunteers could be gathered or it was joined to another company before it was assigned to a regiment. Presumably, these standards were enforced or relaxed as times required. When a company was assigned to a regiment a letter from 'A' to 'K' was assigned. (Letter 'J' was not used! Some suggest that the reason it was not used is because it sounded to much like 'A' when yelled by command. This would be very true in most European languages in which the 'J' is pronounced "soft".) When Bragg's Rifles from the Fond du Lac and Appleton area came in to camp they were assigned Letter 'E'. Below you will find an image of Company I of the 7th Wisconsin taken in 1862 in Virginia. The photo is from the State Historical Society of Wisconsin.
A regiment was supposed to consist of ten companies plus additional staff. The proclamation by the governor also listed minimums and maximums for this composition. They included a Colonel of the Regiment, a Lieutenant Colonel, a Major, and an Adjutant and a Quarter Master both with the rank of Lieutenant. In addition, each Regiment was to have an Assistant Surgeon, a Sergeant Major, a Sergeant for the Regimental Quarter Master, a Sergeant for the Regimental Commissary, a Hospital Steward (no rank specified), 2 principal Musicians and 24 Musicians for a Band. The required number of privates and officers of companies ranged from 830 at a minimum (10 companies of a minimum of 83 men each) to a maximum of 1010. Thus the total number of men in a Regiment would consist of a minimum of 866 to 1046 men by the Randall Proclamation. The companies of the regiment were typically divided into two sections of five companies -- each called a Battalion.
The Colonel (leader of the regiment), Lieutenant Colonel, and Major may have been elected by the officers (usually one of their own number) or appointed by the Governor. Often the choice of a Colonel or other higher ranking officer for a regiment fell to the Governor. This appointment was often used to reward political friends or to appease the opposing political party. For example Randall (a republican) would appoint a democratic officer to a regiment to help ensure the democrats would remain interested in supporting the war efforts of the state. Once a regiment was formed it was mustered in to the US Army and sent to where ever it was commanded.
In the union army, a group of four regiments, and a brigade general and his staff composed a Brigade. The general in charge of a brigade was given one star and called a "Brigadier General". Rufus King's Brigade, which was to become the Iron Brigade, started with the 2nd WI, 5th WI, 6th WI and 19th IN. By the time the 7th Wisconsin showed up in Washington on October 1st, 1861 the 5th Wisconsin had already been re-assigned and the 7th admitted. As time went on, and losses were taken, more regiments may have been added to attempt to bring a brigade back up to strength. The 24th Michigan Regiment of Volunteers was added to the Iron Brigade for this reason. The sad truth is, that after losses from illness and battle, most brigades could only field half as many men as they had on paper. With new officers forming units back home and claiming new volunteers, few replacements made their way to existing regiments, and their numbers only dwindled.
A brigade was assigned to a Division with three or four other brigades. The general in charge of a division was given two stars and was called a "Major General". Three Divisions were used to create a Corps. A corps was assigned to a Major General as well. A few Corps (three or four) were used to create an Army which also fell under a command of a Major General. The union Army of the Potomac was such an Army. After U.S. Grant became General-in-Chief of the Union Armies he was awarded a third star and was called a "Lieutenant General". (Grant did not directly command the Army of the Potomac. General Meade retained that honor after his victory at Gettysburg.) After 1866 U.S. Grant became the Union's only "Full General" with four stars. Grant was the only Union General of the Civil War to wear three or more stars.