Mexican Caesar

 is a mission in Red Dead Redemption given to the player by Captain De Santa.

Story
As John Marston arrives, Captain De Santa and one of his men are forcefully moving women along, meant for the entertainment for Colonel Allende. Marston is then told that Bill Williamson and Javier Escuella are riding with the rebel leader Abraham Reyes.

Allende wants Marston to escort a train, a dangerous job, in exchange for 20,000 pesos and information about Escuella. Marston, of course, accepts. However, Allende does not provide Marston with the money after completing this task.

Walkthrough
You'll have to ride shotgun in the cart, which will take you to Chuparosa.

After some time, the convoy will be attacked by rebels coming from the right. There will be two waves of three riders, and you have to kill them before they kill any of the Mexican soldiers, or else you will have to restart from the checkpoint.

After fending off the ambush, there will be a period where the man riding the cart will say that the soldiers are new recruits, and imply that this mission might be a set-up from the inside. As you make another turn, three rebels will shoot at you from the hills above you on the left and right.

After this last attack, you'll just have to wait until you reach Chuparosa. Get off the cart and follow the captain to the train, where he'll tell you to man the gatling gun during the train ride. During this mission you will have to not only make sure the rebels don't explode the train engine, but also avoid getting killed yourself. After about a minute, the rebels will start attacking on horse from both sides of the train.

After fending off the first wave, you'll reach Las Hermanas, where some rebels will be waiting at the station. Rebels will also still come, constantly, on horseback from both sides. After you exit the tunnel after Las Hermanas, some will probably make their way onto the train, in which case you will have to shoot both at the cart right behind you, and at the horses, still coming in from the right and the left.

Once you start going uphill, just south of Brittlebrush Trawl, there'll be rebels with guns and molotov cocktails waiting in the hillside to the right. Keep the gun level while shooting, as this is the only way you'll get them all.

After this you will only have to ride the train all the way into camp. When the train stops, get off and join the Base Commander, who'll want to talk to you, and thank you.

Bugs

 * On Xbox 360, the game sometimes will freeze just before Las Hermanas. This will require turning the whole thing off and on, and you'll have to restart the mission again.