Originally Posted by
KT550
The bts.gov website should give you the domestic U.S. flights.
It will not show cross border flights to Canada though. If it's a multi sector flight that originated/terminated elsewhere in the U.S. and you are confident it kept the same flight number you should be able to search the prior/subsequent sector.
See this link for the arrivals page. Departures are also listed.
https://www.transtats.bts.gov/ontime/Arrivals.aspx
(I couldn't edit my previous post).
Your Delta flights that were operated by a regional/franchise will be listed under the operating airline, not DL.