The Chester County Archives has many resources online. One of which is the Marriage Records from 1885 to 1930. There are two O'Flaherty boys listed: Hugh and Michael. Both are my great grandmother (Catherine O'Flaherty Welsh)'s brothers. Hugh (b. 31 May 1869) married Kathryn Dee on 4 November 1903. Michael P. (b. 20 August 1871) married Margaret McQuade on 29 January 1902. There were also two O'Flaherty girls. One was my great grandmother Catherine (b. 2 October 1885) showing she married Martin Welsh on 27 April 1910. That same day, a Margaret O'Flaherty (b. 29 June 1870) married a Thomas Graham. While Catherine and the boys did have a sister Margaret, she lived only abt. 1877 to 9 June 1895. All were married in Phoenixville.
The Marriage Records from 1852 to 1855 does not list any O'Flaherty. Their first children were born in 1968 - twins named James and Mary. I have only been able to find Dennis and Martha on the 1870 and 1880 Census records. He died before 1904, when she is listed in a City Directory as a widow. I have been working on the assumption (as in my grandmother - Mary Welsh Still - said so years ago) that Dennis and Martha immigrated individually and met and married here. Ellis Island did not open until 1892. By that time they were here, married and living in Phoenixville.
While I have been unable to find out information on Dennis and Martha Durkin O'Flaherty's marriage, I did confirm three family members and find an O'Flaherty who does not fit in.
Wedding Wednesday is a GeneaBlogger daily blog prompt to display those old wedding photos or scan wedding invitations and announcements. It is also a nice way to sort through marriage information.