Texas Defender gave a couple informative links. Yes they were used w/ dubious success. At Vicksburg they were used heavily w/ some being thrown back and forth between the trenches. I cannot recall anywhere else where they were used in any real numbers. Of note Vicksburg is also the last known battle where anyone ever used a catapult, about knee high and it was used to lob "unmentionables" into the CS works. Bored soldiers are dangerous.