You did not sell the relinquished property -- you exchanged it. As part of the details you fill out for the 1031 exchange, you include the adjusted basis, accumulated depreciation, etc. I am hoping you used a Qualified Intermediary ( QI ) because the QI final report would include all of these details.
If you exchanged by yourself -- a simultaneous event, you perhaps should consider using a professional tax person ( familiar with 1031 like kind exchange) -- could be big headache else.
I have multiple 1031s with QI