Your post tickled my curiosity, so I talked to the heirloom seed person at Hastings. She spent the morning doing some research and discoverd that seeds no longer exist for White Lightning. It is no longer even listed in discontinued seeds. She checked several seed references for the past ten years. It is not in any heirloom lists or any other lists of seeds currently in production, for sale, or for exchange.
The closest she came was finding one source for White Velvet: Adams Briscoll seeds in Jackson, Georgia. Their number is 770/775-7826 if you want to contact them.

Something called South Carolina Seed Production also lists a white okra, but it is definitely not White Lightning. So unfortunately, you are hankering for a seed that no longer exists. So unless you know a family that has planted the same okra seeds for 70 years of more and those seeds retained their original characteristics, it's gone.

sugarhill
Thank you for taking the time to find that information out for me.

Just got a mailing from Park Seeds. They haven't got your White Lighting, but are offering Silver Queen okra. From the text:

"Our Great-Grandparents' Prize Okra!
This hard-to-find heirloom is renowned for flavor and tender texture."

Love the fact it doesn't have to be picked early to stay crisp.

Hope this helps,
Rosie in Sugar Hill

Here is a link that might be useful: Silver Queen Okra at Park Seed

Thank you Rosie

There is a guy from Washington State selling heirloom white okra for $2.05 for 250 seeds on ebay. Looks a lot like it could be white lightening. Do an ebay search for "white okra" - his seller id is "heirloomvegetables." BEWARE - his seeds are cheap, but his shipping is a rip off! Bid or buy accordingly.

It was an AAS winner for 1938 or 1939 and listed on their website. AAS unfortunately does not list a current (as of May 2020) source. U.S. Germplasm sources may have it preserved but did not research that angle. Also seed catalogs of the period may list (with or without photos.) A shame that it has disappeared but sometimes better varieties supercede older ones but then again some vanish due to lack of interest, bad season and who knows what else. Everyone is encouraged to shepard a few varieties of their favorites and to pass them on and keep records in case they go endangered. We are the stewards of the past by keeping them alive in the present.