As with many other Union regiments in the Civil War, the 16th O.V.I. was actually formed twice, the first time in April, 1861, for just 90 days. This short duration was because the government was sure the rebellion would be put down within just three months. The 90-day regiment was mustered out and dissolved in August, 1861. Due to the continuing war, additional troops were needed and the 16th O.V.I. was again formed in September, 1861, but this time for three years. Although not all 90-day soldiers re-enlisted, some did enlist again in the 16th O.V.I. but others in different regiments and, this time, for a long three year term. When you are researching a soldier, please remember he may have appeared in the 90-day or 3-year regiments or both. Additionally, as a result of the Federal Militia Act of 1862, Ohio complied by conducting a draft in the fall of that year. This resulted in 89 men being drafted into the 16th O.V.I. for a term of nine months. These soldiers served in the 3-year regiment from October 8, 1862 to about August 12, 1863, unfortunately for them, the bloodiest period in the 16th's history.  This website currently provides full information on the 3- year, 90-day and 9-months soldiers.