He had a boyish enthusiasm for warfare and was delighted beyond words to be made a colonel in the Illinois National Guard without ever having done anything to merit it other than to exist as a rich person.
The quote highlights the character's naive excitement towards military life, emphasizing a certain innocence and almost childlike enthusiasm for warfare. His joy at being promoted to colonel in the Illinois National Guard is portrayed as unwarranted, as his ascension comes not from merit or experience but merely from his wealth and status.
This situation reflects a broader commentary on privilege and how social advantage can bypass the usual paths of achievement. It underscores the absurdity of a system where one's financial standing, rather than their qualifications, can lead to significant accolades and responsibilities.