User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-24849873-20140809155616/@comment-1153722-20140809200755

As for why Philadelphia was not used, it's a boring city. As you can see on this 18th century map of the city, it consists entirely of straight streets and blocks. Imagine how bland it would be to play through this.