Marriage records are not a matter of vital statistics which covers births and deaths. Therefore you cannot obtain copies of marriage certificates from the state. The Clerk of the Orphans' Court in Washington County was required to keep marriage records beginning 1 October 1885. You should always write to the county, not the state, for marriage certificates. Be aware a small minority of people who apply for marriage licenses do not actually get married, so you should always look for the returned license.
Applications contain the name of the bride and groom, their parents' names, and their age.
They sometimes contain other information depending on what part of the century the marriage took place. For the period 1682-1893, virtually no official state or county records of death were kept. For deaths before 1893, you should look at grave headstone inscriptions , bible records , census mortality schedules , military records , mortuary records or naturalization records , published genealogies , or obituaries . Note that for the period before 1893, some cities did register deaths, and among those close to Washington County are Pittsburgh and Allegheny City. Microfilm of the Pittsburgh records are housed at the Carnegie Library of Pittsburgh .