Thunder On the Mississippi is the latest design in the award-winning Great Campaigns of the American Civil War (GCACW) series. It depicts Maj. Gen. Ulysses S. Grant’s 1863 campaign to capture Vicksburg. The game is designed by Joe Balkoski (the original GCACW series creator) and Chris Withers. The game map will adhere to the accuracy and high graphic standards of its predecessors, with map design executed by artist Charlie Kibler—whose work on the series dates to its creation in 1992. 

Thunder On the Mississippi uses the latest version of the GCACW Standard Basic Game Rules, which also apply to all other games in the series. After more than a quarter-century of refinement, these rules are extremely well organized and relatively easy to learn, even for series newcomers. Two new terrain features unique to the Vicksburg region are also introduced: loess hills and coastal bluffs. The Advanced Game rules cover situations specifically applicable to this unique campaign starting with an amphibious invasion, followed by sweeping cross-country movement ending in siege warfare.

Thunder On the Mississippi includes eleven Basic Game scenarios and one Advanced Game campaign, all extensively playtested:

• The Battle of Port Gibson (May 1, 1863, 1 turn): Introductory scenario, great for learning how to play. Port Gibson was the key to containing the Union invasion, so a scattered Confederate force had assembled there. The difficult and unique “loess” terrain helped the significantly outnumbered Confederates slow down and mitigate the effects of the Union assaults. However, the 3-to-1 Union manpower advantage eventually caused the Confederates to retreat.
• Invasion & Breakout (April 30 – May 4, 1863, 5 turns): The Union invades at Bruinsburg and the Confederates race a few brigades south to Port Gibson to block them.  The Union battles to take Port Gibson and then secures Grindstone bridge to cross the Bayou Pierre. Additional CSA forces have reinforced the area but are poorly positioned to block the Union advance to Willows. The Union begins to cut off Grand Gulf and the Confederates retreat across the Big Black River.
• Unite Your Troops (May 3 – 6, 1863, 4 turns): What if Pemberton responded to the loss of Port Gibson by sending more troops south to protect the port of Grand Gulf and keep the Union from breaking out into the interior north of the Bayou Pierre at and beyond Willows? How well and for how long could the Confederates have blocked the Union?
• Yankee Blitzkrieg (May 10 – May 14, 1863, 5 turns): After the Union paused to resupply and bring in Sherman’s corps, Grant orders a wide front advance from Rocky Springs to the Northeast to cut the railroad between the Big Black River and Jackson. The Confederates shift the bulk of their force to east of the Big Black, just south of the railroad.  CSA reinforcements also start streaming into Jackson and move southwest to Raymond where a battle develops on the 12th. 
• Loring’s Memorandum (May 12-15, 1863, 4 turns): Loring’s May 9th memorandum was a plan to attack across the Big Black River with two divisions at Baldwin’s and Hall’s ferries in the Union rear while Bowen’s division south of Edwards and troops from Jackson enveloped the Union from the north. While Pemberton ignored this communication, it was a viable plan, especially if augmented by more brigades from the Vicksburg defenses.
• Grant Moves West (May 15 – 17, 1863, 3 turns): After the battle of Jackson on May 14, the Union moved west toward Vicksburg. This includes the timespan of the battles of Champion Hill and the Big Black Bridge redoubts.
• Champion Hill (May 16, 1863, 1 turn): The historic battle of Champion Hill, in which the Union army decisively defeated the Confederates.
• I Move at Once (May 16 – 17, 2 turns): A what-if battle scenario in which Pemberton follows the orders he received from Johnston early on the 14th to meet up with Johnston around Clinton. Historically, Pemberton moved to the southeast to Champion Hill to try to gain good ground on the Union supply line. If he had followed orders, with Jackson having fallen on the 14th, Pemberton would have taken an indirect route to the north of Clinton to not collide with the full Union army before he could combine forces with Johnston. Grant had good intelligence on Confederate movements and intended to attack Pemberton before the two armies could join.
• This Is Success (May 17 – 19, 1863, 3 turns): After the battle of Champion Hill, the Confederates retreated first to the region of the Big Black bridges, and then to the forts around Vicksburg. The Union routed the Confederates from their redoubts in front of the Big Black bridges on the 17th. On the 19th the Union made multiple attacks on the Confederate forts at Vicksburg, but was easily repulsed.
• Army of Relief (June 9 - 11, 1863, 3 turns): Johnston had assembled 28,000 infantry in early June to relieve the siege of Vicksburg.  These troops were both at Canton (northeast of Vicksburg), and Jackson. Grant was just starting to receive significant reinforcements, anticipating an attack by Johnston. Grant formed a makeshift command under Sherman to block Johnston. Historically, Johnston made no appreciable effort to relieve Pemberton – he missed his best opportunity to attack in early June before Grant got several new strong divisions. This is a hypothetical scenario depicting what might have happened had Johnston moved aggressively against Sherman and caught the Union command by surprise.
• Inflict All the Punishment You Can (July 6 – July 8, 1863, 3 turns): Johnston finally moved close to the east side of the Big Black River in early July but never crossed it to break the siege of Vicksburg. Sherman meanwhile had built up an Army of Maneuver to not only block Johnston, but also to attack and destroy his army. Historically, Johnston withdrew to the east on July 6th, and Sherman slowly pursued him to Jackson. In this scenario the Union player knows he must move aggressively to pin and attack some or all of Johnston’s army in the open field. Grant’s orders to Sherman were “I want you to drive Johnston out in your own way, and inflict on the enemy all the punishment you can.”
• The Vicksburg Campaign (Advanced scenario, April 30 – July 8, 1863, 1864, 70 turns): A depiction of the entire campaign from the landing at Bruinsburg to the surrender at Vicksburg to the Union pursuit of Johnston back to Jackson.

Thunder On the Mississippi contains:

• GCACW Series Rules Booklet (24 pages, including illustrations, play examples, charts) 
• Thunder On the Mississippi Rules Booklet (about 56 pages, including scenarios, the Game as History, Gazetteer, etc.)
• Two 22"x 32" full-color map sheets
• Two 280-piece counter sheets and one 140-piece half counter sheet
• One Terrain Effects Chart
• Two full-color Force Displays 
• Two 4-page full-color Charts and Tables
• Two 6-sided Dice