Sway fierce battles in your favor with the powerful WarChief and lead one of three great Native American civilizations. Take the next step in the battle for control of the Americans with the WarChiefs Expansion Pack for Age of Empires III. Age of Empires III: The WarChiefs is the first expansion pack for the real-time strategy game Age of Empires III. It was released on October 17, 2006 in the United States. The expansion pack was bundled with the full game of Age of Empires III, called Age of Empires III Gold Edition on October 23, 2007. The Mac version was ported over, developed and published by Destineer's MacSoft. The full game for Mac was released on June 12, 2007 in the United States. It was followed by a second expansion pack to the original game called Age of Empires III: The Asian Dynasties.

The campaign, which is 15 missions long, includes the Black family in a more historical setting. The first act, Fire, follows Nathaniel Black (John Black's son and Amelia Black's father) as he spends the family's entire fortune supporting the American Revolution. The second act, Shadow, follows Amelia Black's son, Chayton Black, and his actions in the Black Hills during Red Cloud's War and Great Sioux War. The home city for both acts is the Black Family Estate. Act 1: Fire Nathaniel Black (loosely based on Joseph Louis Cook) is the half-Iroquois son of the late John Black from Act 2 in the previous game, raised by his mother Nonahkee and his uncle Kanyenke. The campaign opens as Nathaniel and Kanyenke are trying to discourage the Mohawk and the Seneca from fighting in the American Revolutionary War. However, they are ambushed by a group of Mohawks and head to an Oneida village nearby. From there they counter-attack and destroy an enemy Town Center, thus causing their enemies to flee. When Nathaniel and Kanyenke return to their village, they find that the Mohawk and a group of Hessian mercenaries led by Colonel Sven Kuechler, have raided the village and captured Nonahkee. They rescue Nonahkee, but Kuechler and his main army escape, leaving the Iroquois Confederacy to dissolve. Nathaniel's village supports the colonists, and Nathaniel heads to Boston where his men help defend a redoubt on Breed's Hill from the British. After George Washington takes command, a series of defeats drives the colonials back across the Delaware, where they are joined by Nathaniel. Here, Washington leads a small force, including Nathaniel, across the Delaware where they attack a Hessian encampment at Trenton and defeat the rearguard of the army at Princeton. This is followed by another victory at the Battles of Saratoga. However, the army is once again defeated at Brandywine and Germantown and is forced to camp for the winter at Valley Forge, where they suffer greatly from the cold. This leads Nathaniel to use most of his family's fortune to supply the army throughout the winter. The next scenario is the fictional battle of Morristown, where Nathaniel has his chance for revenge on Kuechler, who leads an attempt to destroy the capitol building of Morristown. Using artillery shipments he receives from Washington, Nathaniel sneaks around the Hessian flank and relieves Morristown. Refusing to accept defeat, Kuechler joins the fight with Nathaniel and is killed. After Kuechler's death, Nathaniel is said to have fought at Charleston, Camden, and King's Mountain. As the tide begins to turn, the French join the war and help the revolutionaries gain a victory at Yorktown, where Nathaniel is instrumental in capturing several redoubts. With the Revolution won, Nathaniel returns home a poor man having spent his family fortune on outfitting his volunteers and supplying the troops at Valley Forge. During the epilogue video of the campaign (where Nathaniel is at Yorktown), the "Old Coot" (secretly Morgan Black) from Acts 1 and 3 in the previous game can be seen watching his great-grandson's victory.