Conversation so far:
What can you tell me about Albert Sydney Johnson's Concentration at Corinth?
Albert Sidney Johnston decided to concentrate forces with those formerly under Polk and now already under Beauregard's command at the strategically located railroad crossroads of Corinth, Mississippi.
Where did Albert Sidney Johnston have forces with those formerly under Polk?
Albert Sidney Johnston's troops were in the vicinity of Nashville.
Are there any other interesting aspects about Albert Sidney Johnston besides troops in the vicinity of Nashville?
Albert Sidney Johnston also reinforced Fort Donelson with 12,000 more men, including those under Floyd and Pillow.
Was Albert Sidney Johnston successful at reinforcing Fort Donelson?
Gen. Simon Buckner, having been abandoned by Floyd and Pillow, surrendered Fort Donelson.
Does it state how many men Albert Sidney Johnston lost at Fort Donelson?
The Confederates suffered about 1,500 casualties with an estimated 12,000 to 14,000 taken prisoner.

Question: Who did he serve with?
Self-contained rewrite: Who did Albert Sidney Johnston serve with?