Thanks for all the info. To answer your question about Janie Meldrum and the Hockaday family, she appears on the 1870 US Census under the name Jane Meldram. Place of residence listed as Antioch, Lake Co Ill. Also living in that household was a Charles Martin age 35 and a John Mcguire age 16. William Hockaday seems to be head of house, age 38. His wife Amanda, age 36, child Ida 10 & Cynthia age 7 round it out.
As for DOB for William, all I know is it's about 1815 or 1816, likley in Aberdeenshire, Scotland. Though I have no proof of that. However, there is a marriage record dated to Dec 1849 for Old Deer and my guess is that's where he was born.
Thanks for the birth/death cert tip! I will check it out. Let me know if there's any info I can provide for you regarding this family.