I had to request a certified copy by mail (the Internet wasn't really a thing yet, so there was no "doing it online").

It was still "request by mail" when I obtained certificates for both of my parents. In PA, there is a central location for all births in the state. I found, on line, an alphabetized list for all births in the early 1900s. Scrolled through and found my dad's, and learned he was born in Yardley, in Bucks County, and both of his parent's names. Mailed off the form with that information on it, and a check, and the certificate meandered in, eventually. In Michigan, the records are kept at the county level. I have a certificate of birth registration for my mom, which gives date and county. That county required I enclose a self-addressed, stamped, envelope, for them to mail the certificate to me. Threw me for a moment, when I opened the mailbox, and found an envelop addressed in my handwriting. For my paternal grandparents naturalization records, I made the request on line, in July 24. On March 31, 25, I received a reply they had found some documents and would mail images of them to me, on a CD. A couple weeks later, the CD showed up, with images of the statement of intent to become a citizen, application for citizenship, and the Certificate of Naturalization. As was the practice in 1921, the paperwork for my paternal grandfather lists the entire posse, so my dad was both born in the US, and a naturalized citizen.

Steve