Common name rule puts it at Manassas http://books.google.com/ngrams/graph?content=Second+Bull+Run%2C+Second+Manassas%2C+2nd+Bull+Run%2C+2nd+Manassas%2CBattle+of+Second+Manassas%2CBattle+of+Second+Bull+Run&year;_start=1800&year;_end=2000&corpus;=0&smoothing;=3&share;=