The May 24th Top Tenz web site had a list of the ten worst Civil War generals. After the name, they listed why. I'm just going to list the names.
10. Hugh Judson Kilpatrick, US
9. William S. Rosecrans, US
8. Don Carlos Buell. US
7. Gideon Pillow, CS
6. Nathaniel Prentiss Banks, US
5. Franz Sigel, US
4. Braxton Bragg, CS
3. Ambrose Everett Burnside, US
2. George Brinton McClellan, US
1. Benjamin Franklin Butler, US.
Of course, this list is one man's opinion. However, I'd have to say that the ones listed certainly had major defects when it came to command.
Number one was quite involved in the first attack on Fort Fisher. His failure there ended his military career.
And These Guys Commanded Soldiers? --Old B-R'er