The marriage is listed in the index of Philadelphia marriages just like with Manning and Mortland. It's a cross reference between the first names (just type in the last names). I knew approximately when they got married and looked for a match: https://www.familysearch.org/s/collection/show#uri=http://search-api:8080/searchapi/search/collection/1388247&hash=Mrd8SMocDIIen2Q83tu%252B82PRagg%253D
I suggest getting both marriage records while you are at it. They were originally at the Philadelphia Register of Wills, but might now be at the Philadelphia Archives. I believe they are also on microfilm through the LDS Family History Centers.