The Hugh Sheridan, that I have been researching, appears to have been from another Sheridan Family who lived in New Castle Town. All-things-being-equal it appears that he may not be one of your immediate ancestors. But then again he may be, as he was also a Sheridan. My confusion is that great-grandmother Mary Helen (née Sheridan) Doherty did have a younger brother, great-granduncle John J. Sheridan who was born 22 November 1867, (see Part 724s) and this Hugh's elder brother was also named John J. Sheridan.
The other John J. Sheridan was born in the 1860s as well. This one, according to the 1920 US Census had eight children, the eldest being 22 years old in 1920. He is the one who had a younger brother named Hugh. I believe that their father's name was also Hugh. In 1920 this John J. Sheridan family, including his brother Hugh lived at 29 West Fourth Street in New Castle Town in New Castle County. (Accordingly this is now "Old New Castle".)
So you can now understand the confusion... Two John J. Sheridans, both born in New Castle County in Delaware in the 1860s. Both had siblings with similar and near closely related names. Both were from Irish Catholic families. Both lived at or in the vicinity of a street with the name of Fourth, 4th. The key point is that one was married while the other, your great-granduncle John J. was single.
Pleased note that the "greats" and "grands" designations are as the individual relates to Andy.
And now you see how miniscule details can make the difference on identifying who may or may not be an immediate ancestor and relative.