Green’s Dictionary of Slang

(US) San Diego, California.

1918		St John’s Rev. (OR) 9 Aug. 1/4: We’re in San Diego Bay / When we get some coal and chow on baord / We’ll then be on our way. / From Dago town to Panama, / We sure did hit the trail.
1944		H. Hunt East of Farewell 78: This is a hell of a summer [...] I wisht I was back in Dago.
1953		L. Uris Battle Cry (1964) 68: What are you going out for when we get back to Dago?
1970		San Diego Sailor 9: I [...] beat it to Dago and joined the Navy.
1994		(con. 1941) A. Kernan Crossing the Line 14: The streetcar clanged back to ‘Dago’ where the streets were filled with sailors on liberty.
2019		D. Winslow Border [ebook] [T]hen hit the road back to Dago [...] he didn’t want the courier knowing he lives in San Diego.
2020		D. Winslow ‘Crime 101’ in Broken 73: ‘You might want to keep away from Dago’.