Southgate Fort was a fortified location built around Boston's southern entrance, on top of the Boston Neck. During the French and Indian War it was partially maintained by Silas Thatcher and his unit of the British Army, including a general, used as a location for detaining Native slaves.
In the early 18th century, the only accessible land-route to Boston was across the Boston Neck. In order to establish protection from potential attacks, fortifications were built around the area, which was known at the time as the Southgate Fort. By 1754, Silas was the man in charge of the fortifications, which he used to house slaves he had round up from various areas in Colonial America. One of the many tribes which had members enslaved were the Mohawk, which the Templars had taken an interest in after a precursor artifact was discovered.
When the Templars discovered that some of the slaves were from the tribe they sought, Haytham created a plan to infiltrate the area. After raiding a convoy, they went in as a Trojan Horse to 'deliver' the slaves. After Haytham killed the fort's general and freed the slaves of the area, he continued in order to kill Silas with the help of his co-conspirator, Benjamin Church.
During the Siege of Boston in 1775, Massachusetts Governor Thomas Gage had the fortifications of Southgate strengthened and expanded to protect the city. It was then known by most as Gage's Lines.
In the 19th century, land was added to the Boston Neck so that there was more room for the city to grow and to ease the traffic of the area. By this point, the fortifications weren't increased, since there was no longer a threat of attack from the countryside.
- Despite the Boston Neck Database entry explaining that the fort was given better fortifications during the Siege of Boston, the area did not change in size or even population.
- If the weather was altered to be winter via the aid of an Animus hack, Southgate Fort would be abandoned and muskets would be missing from the landmark.