Examples of US medal engraving styles.

Below are assorted images of American medals illustrating original period naming & numbering styles.
The attempt is more a photo essay than text.

US Army Campaign medal No. prefix numbering.

US Army Campaign medal M.No. prefix numbering.

Plain numbering on campaign medals

(below) Army Civil War Campaign Medal

(below) US Navy Civil War Campaign medal numbering.

BB&B numbered USN Campaign

Campaign medal rim engraving.
Officially done by order of the Navy. Typically slanted capitals done on either side of the number.

Impressed naming on a Sampson medal.

Navy Specially Meritorious Service Medal

USN Good Conduct medal naming.

US Treasuring Silver Lifesaving medal

USMC Good Conduct Medal engraving.

USMC rim number

USMC Gold Distinguished Marksman's badge

Rim numbering on Army decorations WWI-WII
Numbered rim on Army Distinguished Service Cross

Numbered rim Silver Star

Numbered rim Purple Heart

1930's Purple Heart & Silver Star hand engraving as issued to WWI (and earlier) recipients.

The medal, shipping box, and medal box.

Officially hand engraved 1932 contract BB&B Silver Stars.
The example to Craney was issued for Gallantry in the Philippine Insurrection, the example to the right for service at the outset of WWII.

Typical WWII US Army hand engraved medals.

Note: Rank & A.C. on Air Medals & DFC's. Name only on Purple Hearts.

Typical of the pattern engraving found on Silver Stars, Legion of Merits & Bronze Stars.

Stamped "pantograph" naming.

An engraved WWII Distinguished Service Medal

Below shows post WWII pattern script engraving.
Generally attributed circa 1948 as seen on awards sent out at the wars end such as CIB conversion Bronze Stars.

WWII pattern official USN engraving examples.

USN Silver Star / Purple Heart pair

Fully engraved DFC

Late WWII pattern official USN engraving.