As seen in the movie "Oppenheimer". The Endicott was introduced in 1938 and ran through 1948.  It was a very popular model and is found in two most common dial patterns. The earliest Endicott came with the AGN dial with rectangular hour markers as well as a black enamel dial. This example is the rare Black Enamel dial variant.

The watch Runs.

A perfect gift for Fathers Day or Graduation

Service History unknown. 

Running but sold As-Is.