The Diocese of Boston was erected in 1808, and encompassed much of the northeastern United States. After that there were changes to the territory, both additions and removals.
The site http://www.catholic-hierarchy.org/ has information on both current and historical dioceses worldwide and should be of help.
If this does not help, you might try contacting the archives of the Archdiocese of Boston for assistance.
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Although Catholic Canon Law apparently permits a wedding outside of a church with the permission of the Bishop, they are typically reluctant to approve it, at least currently. The sacramental and spiritual aspects of the wedding would argue against approval.
In other churches, and possibly longer ago, marriage was considered a civil affair and not in the purview of a church. The Catholic Church used to view a civil wedding as not really valid; for example if someone had a civil marriage and was later divorced, they could subsequently get married by the Church; whereas one could not be remarried in the Church after a civil divorce of a Catholic wedding.