Adrienne -- The 51st Regiment Arkansas Militia was part of the old prewar militia system of Arkansas, but continued to muster during the war up to March 1862. There are no descriptive rolls that I am aware of. However, you can reasonably assume that your connection regarding William Levy is accurate. This is due to the fact that under the Arkansas militia law, regiments were organized on a county basis -- one regiment per county (a couple of counties had two regiments). The 51st Regiment was the militia regiment of Sebastian County. The component companies (normally ten per regiment) were loosely organized on a township basis. In most cases, you can set the roster down next to the 1860 census for that county, and just tick off name after name. In the case of the 51st Regiment, the William Levy on the 1860 census of Fort Smith is the only game in town, and therefore must be the William Levy in that regiment. The odds of another William Levy suddenly showing up from somewhere and enrolling in the regiment are pretty remote. Unfortunately, in the case of the militia regiments, that is about as close to a smoking gun as you're going to find. I hope this helps a little.