William (28) and Sarah Whittaker (30) (I assume they are man and wife)
went to Philadephia from Londonderry
Address Glencash, Clonleigh, PO Co Donegal
in Feb 1866 and also Jul
I wondered if anyone can give me any help on finding their marriage/anything on them in US or if someone can explain the above to me please?
How can I fid out more on them please can anyone help - marriage/where they were in US/ born etc., anything will be of interest.
First of all, you can't assume that William and Sarah were married to each other- they might be brother and sister or more distant relatives.
Before you can do any more searching in Ireland (will explain why in a minute) you need to find as much detail in American records on them.
Starting with earliest possible census records you can check 1870, 1880, 1900, 1910, 1920 and 1930.
1880 is at
www.familysearch.org (free)
LDS Pilot site has the following indexed (free): 1870, 1880, 1900, 1920
http://pilot.familysearch.org/recordsearch/start.html#r=0;p=allCollectionsThere are other U.S. records there like Philadelphia marriage indexes and death certificates which might be useful if they actually stayed in Philadelphia.
If they died somewhere in U.S., depending on the actual state and period, the death certificate might list their birthdates and places, names of parents, etc.
Now for the Irish side. Civil registration of births, deaths and Catholic marriages started in 1864 (from 1845 for other marriages). First complete census for Ireland is 1901. If they were not married in a Catholic church and it was 1864-1866 then you might find the marriage certificate to get more details like their residences at the time of the marriage and their fathers' names and occupations. However, it might be that you will have to start searching for church records (which may or may not exist) so you need to get as much information before you start looking in Ireland.
