He wasn't exactly a General, but was mustered as Major, and was later promoted and ultimately discharged (actually resigned) as a Lt. Col.

He was honored for War Service by Brevet to Colonel and Brigadier General 13 March 1865.

FEB. 17, 1899.
"MY DEAR FRIEND- As this is my sixty-fourth birthday I thought I would say all hail! to the few thousand chess players I have met through my favorite chess column in THE N. Y. CLIPPER. As this may be the last time l shall trespass on on your valuable space - [No, sir!] - a few facts of my chess career may be a pleasant reminder to my chess friends. I am now one of the oldest of the galaxy of chess enthusiasts. I learned the moves in New Jersey in 1857, inspired by the brilliant performances of Paul Morphy. From that time to the present l have loved the noble game more than anything else. I never desired very high rank as a player, but in my personal play with celebrities I held my own with many of the best and defeated many celebrities who did not want those games published. I enlisted as a private in the Union army, April 19, 1861; attained the rank of Lieut. Col. of cavalry; and, at the close of the war, was honored with two brevets - Colonel and Brigadier General; for distinguished services. I met no chess players in the army that I failed to vanquish. On returning to civil life, several old intimates congratulated me on my many promotions, and asked how I was so successful. I told them it was chiefly through my skill in chess ; that military science was easily acquired by a chess player. I have taught the moves to over 2,000 beginners; and have played with over 5,000 different players. I have visited 500 chess resorts; have owned over 300 different chess books and given them all to young players. I have subscribed for, or purchased from one to three chess columns per week, and subscribed for or purchased all the German, French, British and American chess magazines for over twenty years, and have generally given them to chess friends, after studying them as much as I deemed advisable. In my recent visit to the chess resorts of New York, Phila., Baltimore, Washington and Chicago I was grieved to hear of scores of chess players who had died during my twenty years absence from those clubs. Dear Hazeltine, we have been friends in chess for over forty years. It has been a pleasure to be with you in spirit almost every week of that long time. Old age and poor health admonish me that I shall not attain a marvellous longevity, but while reason holds its throne I shall love chess and do all I can to further its interests. Farewell ! Farewell !! Farewell !!! With greetings to all; I am yours truly, JAMES A . CONGDON.">