Check In Time question

At the end of March, I leave for L. A, .. my departing flight from
Lexington, KY to LA , connecting in Atlanta leaves at 6:20 AM.
Bluegrass Airport is a small airport, do I really need to be at the
airport two hours before the flight?

Two hours? Naah.

In my experience, at small airports the main bottleneck is the
security inspection where there's only one x-ray and one metal
detector. The OAG shows three or four flights leaving around 6:30, so
it may be kind of busy.

From the airport's own web site http://www.bluegrassairport.com:

* We recommend arriving early for flights. 60 minutes should be
sufficient for most flights but for flights departing Su-F from
6:00am to 8:00am or during Holiday periods allow at least 90
minutes to check in and clear security.

If you plan to leave your car in the econo lot, remember to allow a
few extra minutes for the walk through the garage to the terminal.

At my home airport, Ithaca NY, 20 minutes is usually enough time and
30 is plenty (add two minutes for long term parking), but that's kind
of an extreme case.

Regards,
John Levine, , Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://www.johnlevine.com, Mayor
"A book is a sneeze." - E.B. White, on the writing of Charlotte's Web

I would think 90 minutes would be sufficient, no?

As others have observed--almost meaninglessly early. Particularly if you
check in online and have no luggage. Online check-in is an excellent
option--even if you have a flat tire on the way to the airport and make it
to the gate with 20 minutes to spare, you are in decent shape.