The US military has valid reasons to maintain a level of secrecy surrounding its operations, but historical blunders have exposed some of the darker aspects of its work. In certain instances, concrete evidence has come to light, unveiling disturbing secrets, while in others, leaked snippets of information have prompted the public to speculate and construct conspiracy theories.
Here, we explore some of the once-secret operations undertaken by the US military, along with the conspiracy theories that have captured the attention of many Americans. Click through the gallery to get started.