Wills provide a fascinating insight into the past, often describing the testator's possessions in detail, as well as identifying all the family members. Sometimes a will is the only proof of a link to that family, as baptism records may have been lost. They are also important in identifying the married names of daughters.
Here is a list of all the people with wills and/or probates in the McKAY family tree. They have been (mostly) transcribed and are available on that person's page: