Simple GBACW

From BoardGameGeek:

Simple GBACW is an alternative to the Series Rules of GMT's acclaimed Great Battles of the American Civil War series. Now players can use the GBACW maps and counters to recreate Civil War battles with a shorter, 16-page rulebook, allowing them to play even the largest scenarios to conclusion in a fraction of the time. The rules retain the feel of linear combat in the Civil War while shifting the focus from the individual regiments to the brigades as a whole. Many of the concepts found in the Simple Version are similar to players familiar with GBACW, but the Simple Version is not necessarily intended as a gateway or a stepping stone to the Series Rules. Currently, the Simple Version rules are only available for 3 Days of Gettysburg – Deluxe Edition, but plans are in place to provide Simple Version Battle Books for both existing and upcoming games.