The '7th New York State Militia, Camp Cameron, D.C., 1861' refers to a specific military unit during the United States Civil War. This militia was part of the New York state forces and was stationed at Camp Cameron in Washington, D.C., around the year 1861. The designation '005' likely represents an internal or cataloguing number within the collection or archive where this particular item is housed. The unit played a role in the broader context of the American Civil War, which took place from 1861 to 1865 and was fought between the Northern states (the Union) and the Southern states that seceded from the United States and formed the Confederacy. This conflict was primarily about the contentious issue of slavery and its expansion into newly-opened territories, leading to the abolition of slavery in the United States.