Fort Mercer

 is a location featured in Red Dead Redemption in the Río Bravo region of the New Austin territory. Fort Mercer is the location of Bill Williamson before he flees to Mexico, and later becomes an outlaw hideout.

Red Dead Redemption
Fort Mercer might have been a fort used during the Mexican-American War as it is near the border with Mexico. Jake speculates that the soldiers abandoned it because they moved up north to fight Native Americans.

It is an important storyline location, as it is here that Williamson remains protected in the fortifications alongside his outlaw companions. The mission "Exodus in America" ends in this location and naturally, it is also the setting for the Leigh Johnson mission &quot;The Assault on Fort Mercer&quot;.

Outlaws to the End
Farmer MacGuffin's daughter must be rescued from  in the Outlaws to the End Co-op mission &quot;The Kidnapped Girl&quot;.

Undead Nightmare
During the Undead Nightmare,  is a permanent Safe Zone, and can never be overrun with Zombies. It has been taken over by the military to house refugees and hold out until rescue arrives. However, there is a constant horde of zombies surrounding it at all times, making it difficult to enter or leave. It is here Marston encounters Nigel West Dickens, who is initially attempting to sell a modified version of his elixir to the refugees hiding inside the fort. This is also one of two locations that the player can begin the Missing Persons activity. In addition to the stack of boxes next to the main gate, there is a ladder on the southeastern facing side of the fort to use for ingress and egress.

Liars and Cheats
It serves as one of the Stronghold matches. This being the only one where one cannot obtain the Explosive Rifle.

Location
is almost due south of the old railroad halt of Mercer Station, up on the central plateau of Rio Bravo. Alternatively, the road east from Plainview and then north up into Rio Bravo approaches the fort from the south.

Description
is a sprawling collection of military buildings surrounded by a high, white perimeter wall.

Walkthrough
The hideout becomes available after Marston accompanies Irish to Mexico in the mission “We Shall Be Together In Paradise”.

A the start of the hideout mission, Mexican Gunslinger Leon Galindo will be outside the walls. He will help the player climb over the wall to start the mission proper. Climb up, kill several Banditos, drop down and open the front gates for him. After this, simply kill all remaining Banditos in Fort Mercer, after which the three Bandito leaders (enemies with slightly more health than regular ones) will burst out of the treasure room. Kill them and the hideout is complete - and one of them will drop the Semi-Automatic Pistol. It is also complete if the Gunslinger enters the treasure room. There is also a Semi Auto Pistol on the boxes in the treasure room. Leon allows you to take all the treasure. There is also a safe on the upper level of the fort that can be cracked, although doing so without wearing the bandana will result in a loss of 100 honor (as with any other safe).

Bugs

 * Occasionally, the Gunslinger will get stuck behind a wooden rack-like object leaning against a wall. Simply run into this object to make it fall over and he will continue on.


 * There is a bug in which after he introduces himself he will stand motionless making the player unable to proceed.

Multiplayer
In multiplayer Free Roam, the fort is occupied by the Bollard Twins Gang. The LeMat Revolver is also located here, in a crate on the roof of one of the rear buildings. There is also a Gatling Gun on the roof of the fort. The Free Roam mission requires the player to simply kill all the bandits in the fort, as well as the Bollard Twins Gang Boss. Among the gang members defending the fort are Gus Ballard, who may appear multiple times, and Slink Bradshaw, a NPC infamous for his superb marksmanship.

Trivia

 * Fort Merceris a real fort that was built during the American Revolution. It sits on the banks of the Delaware River and was headed by George Washington.
 * Fort Mercer is very similar to that of Fort Diego's layout.
 * It is possible to duel the gunslinger, Leon in single player.
 * Oddly enough if the player goes to Fort Mercer before driving Williamson out they can see several Banditos standing around inside, near the top of the walls. They can lasso them and drag them off of it if they're in a good enough position to kill them. Killing them will give no honour change and will add a Bandito kill to the player's stats.
 * Mercer comes from the Old English Merc or Myrce meaning "Borderland". This is plausible as Fort Mercer is on the US-Mexico border.
 * During the Exodus in America mission, Jake will tell the player that, although Fort Mercer has been abandoned for years, it was originally occupied by American soldiers during the Mexican War. He says that even though he heard they left to fight Indians in the North, it's possible they "got tired of being soldiers and went looking for gold, you know how things is." It's possible that this is a reference to the group of soldiers who hid the gold found during the Treasure Hunter Challenges, considering that Fort Mercer has a treasure room located within its walls.
 * Fort Mercer also has the distinction of being the only gang hideout to be occupied by five different groups throughout the game: In single player, Bill Williamson's Gang followed by the Mexican Banditos; in Multiplayer Free Roam, the Bollard Twins Gang; and in Cooperative, Walton's Gang. In Undead Nightmare, the American Army has control over it.
 * In Multiplayer, if the gattling gun is used for a long time it will 'run out of ammo' and dissapear.
 * Very rarely in Undead Nightmare, players can hear something getting hit inside the fort. This turns out to be an Undead that somehow got into a fort. This happens usually at a tower with two soldiers in it. For some reason, the two soldiers do not fire at the Undead attacking them and are often dead by the time you get to the quarrel.
 * After you complete the gang hideout, if you explore Fort Mercer you will find a room with two prison cells occupied by prostitutes. Unfortunately, there is no way to release them.
 * Fort Mercer is one of the playable maps in the game mode Stronghold.
 * In the Undead Nghtmare DLC, at the southeastern side of the Fort (Where the ladder is), by simply standing at that corner a group of about 10-20 Undead will gather at that location and try to attack you as if you were at ground level.

Achievements
 is associated with several achievements:

Undead Nightmare
Keeping this location free of Undead infestation during the Undead Nightmare and rescuing all of the Missing Persons contribute toward the following Achievements/Trophies:

Fort Mercer Fort Mercer