In 1903, he gained some attention for his participation in the rescue of a Venezuelan fisherman off the coast of La Guaira under bad conditions.

During World War I, he first commanded USS Supply and captured German Corvette Captain Adalbert Zuckschwerdt off the coast of Guam.

Nellie was born in Tokyo and married United States Army Captain Franklin Gibney Rothwell in 1942.

[12] Upon graduation, he participated in the Battle of Santiago de Cuba of the Spanish–American War aboard USS Brooklyn.

[14] He subsequently served aboard USS Don Juan de Austria, leaving the ship in 1901.

Believing an explosion imminent within the breechblock of one of the ship's guns, Cronan shoved his hand within the block to prevent its closing.

[19] During his time in command, the ship struck a naval pier at full speed and took several hours to get loose.

[21] Cronan served in World War I as the commanding officer of USS Komingin der Nederlanden, a transport ship, for which he received the Navy Cross.

[22] As the ranking officer present, he took command from outgoing governor William John Maxwell pending the arrival of appointee Roy Campbell Smith.