She was named after Captain Walter Stuart Diehl, USN, a career naval officer and aeronautical engineer.

They were initially built without armaments, but are equipped with small arms and can be fitted with close-in weapon systems if required.

[2] Walter S. Diehl, the seventh ship of the Henry J. Kaiser-class, was laid down at Avondale Shipyard, Inc., at New Orleans, Louisiana, on 7 August 1986 and launched on 2 October 1987.

She entered non-commissioned U.S. Navy service under the control of the Military Sealift Command with a primarily civilian crew on 13 September 1988.

On 23 April 2008, Walter S. Diehl was passing through the Strait of Hormuz when six small motorboats sped alongside in an aggressive and threatening manner.