I have been reading two books lately: "The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies. Series I - Volume V" prepared by Ltc Robert N Scott (1882) and "Cavalry Tactics as Illustrated by the War of Rebellion. Part I" by Captain Alonzo Gray (1910). These two books are both availible on Books.Google.com.
They give many examples of the small skirmishes involving cavalry and how they were employed. Captain Gray gives an interesting review of the employment of cavalry weapons of the revolver and saber. The Saber is a shock weapon that after the initial round of combat is less useful. The revolver appears to win in every encounter between saber and revolver. He extends his analysis to those of the early plains engagements prior to the American Civil War.
My question is, how many people actually use cavarly formations in their games other than a line formation? Does anyone move their cavalry in column formation and switch to line to charge?