The Pinkertons were America’s most powerful private army, then Congress banned them

The Pinkerton National Detective Agency played a significant role in the American experience. Its operatives were involved in various aspects of the country's development, including protecting railroads and pursuing criminals in the American West. The agency also played a part in labor conflicts during the industrial age.

The agency's history is closely tied to major events in the United States, including the Civil War. It was founded by Scottish immigrant Allan Pinkerton and became a powerful private institution. Further details about the Pinkerton National Detective Agency's history and activities are available from the source, providing insight into the agency's impact on the country's development.