This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Alligator V. Marine Sergeant Clarence Raper right and Corporal Walter Gibson pose beside the first amphibian tractor procured by the Marine Corps It was tested extensively in under the direction of then Captain Victor Krulak the later author of First to Fight An Inside View of the Marine Corps and the father of Charles Krulak the