This list of wrongful convictions in the United States includes people who have been legally exonerated, including people whose convictions have been overturned or vacated, and who have not been retried because the charges were dismissed by the states. It also includes some historic cases of people who have not been formally exonerated (by a formal process such as has existed in the United States since the mid 20th century) but who historians believe are factually innocent. Generally, research by historians has revealed original conditions of bias or extrajudicial actions that related to their convictions and/or executions.