So when did temple marriage begin? I really can't find a definitive answer.
Eternal marriage may have begun at Adam and Eve, but when did marriage performed in the temple begin?
Edit: For clarification, I'm talking about way back before the modern LDS Church existed. Did temple marriage exist in Bibilical or Book of Mormon times?
Like others, I'm going to ignore the term "temple marriage" and focus more on "sealing" (of spouses). And I'm afraid the answer, as I understand it, is neither simple nor satisfying.
I will break this up into a few different time periods to consider
Garden of Eden to Moses
This is the hardest time period to make any claims, and so my primary assertion is that we just don't know.
Certainly, the ancient records don't make any indication of sealing being a Thing. I don't know