Lucy says that Arnold once spent £1,000 on a bottle of wine, equivalent to around $80,000 USD in 2016. Using the Bank of England's CPI calculator, £1,000 in 1780 (the year that they jump to) is actually worth over £113,000 or $141,250 USD in December 2016 (when this episode first aired).
Lucy refers to Benedict Arnold's horse being shot out from under him at the battle of Saratoga. This actually happened at the battle of Ridgefield.
The gang rides some distance with Arnold to get to Rittenhouse. Then somehow the time machine is nearby when Flynn makes his escape.