I found Arthur J. Baker and Mary in the 1900 U.S. census in Lower St. Clair Township, Pennsylvania. Lower St. Clair Township was annexed to the City of Pittsburgh in 1920. I was able to see the image of the 1900 census on FamilySearch Pilot website. Lillian and Arthur J. are the children. Isaac Yeo is the father in law. Arthur and Mary were married seven years (1893).
The 1900 census has Arthur as being naturalized (no date). He could have naturalized in a local, state, or federal court. Naturalization papers from that era may not have much family information on them.
In the 1910 census (image not on the FamilySearch Pilot site), Mary is a widow. She is living in Ward 16 of Pittsburgh, with children Lillian, Arthur J., Marie, Edith, Alice , and Ruth. Isaac Yeo is listed as parent, meaning that he is probably living with them.
In 1920 (image not on the FamilySearch Pilot site), Mary has remarried to Cosimer Charles. He is Polish, 46, born 1874. Cosimer is probably Casimir. Charles may be an Angilcized name from the Polish. All of the children but Lillian are with them.
You can find these census records by going to
http://pilot.familysearch.org/recordsearch/start.html. Click "Search or Browse our records." Then click on the map of the U.S. and Canada, then scroll down to "United States Census." You can search 1900, 1910, and 1920. For 1900, use Arthur J. as first name and Baker as surname. For 1910, search Mary Baker, then filter by Place, using England. For 1920 search Cosimer first name and Charles last name.
A 1930 directory of Pittsburgh has an Arthur J, Baker (poss. the younger Arthur) living at 2704 Shelly St., which is in Pittsburgh's South Side neighborhood. His occupation is laborer. Given where he lived, he may have been a steel worker at the South Side Works of J & L Steel Co., a very large plant.
The 1936 Whites Pages has Arthur J. Baker at 2901 Sarah St., which is not far from Shelly St.
No sign of Cosimer (Casimir/Kasimir) Charles in the directory or in the White Pages. There is a Mary Charles, but the place of residence is far from the area where the Bakers and Charles' lived in 1900-1920.
The conclusion from all of this is that Arthur J. Baker, the husband of Mary Yeo Baker, died between 1900 and 1910. If he died in or before 1905, the death record (which may or may not have the father's name) is in the main branch of the Carnegie Library of Pittsburgh. If he died after 1905, the death certificate is with the state of Pennsylvania.
Carnegie Library's birth and death record info is at
http://www.clpgh.org/locations/pennsylvania/BirthDeathRecords.htmlThe death record before 1905 may or may not have the father's name. The death certificate after 1905 should have it.
Regards,
John
