Which of the following American flags is the largest?

The Garrison Flag is indeed the largest type of American flag. It is typically used in large outdoor displays, especially on military installations, and measures 20 feet by 38 feet. This flag is designed to be flown prominently to signal the importance of a location or event, demonstrating national pride and respect.

In contrast, the Storm Flag is smaller and intended for use during inclement weather, ensuring that it remains visible despite harsh conditions. The Post Flag is also smaller than the Garrison Flag and is used for daily display at various military posts. The Ceremonial Flag, while it can be aesthetically significant during official events, is also smaller than the Garrison Flag and used primarily for ceremonies rather than continuous display.

The specifications of these flags reflect their intended use, with the Garrison Flag being specifically designed for prominence and visibility, which is why it is the largest of the options provided.