Words Of Champions (officially entitled The Words of the Champions) was the first Scripps-provided study list ever. After it was first released in 1953, it served as the official study booklet for the Scripps Howard National Spelling Bee for 42 straight years, finally being replaced by Paideia in 1995. This list is not to be confused with the new Words of the Champions, the fourth in the line of Scripps-provided pre-national bee study lists, which was introduced for the 2020 Bee Season.
A new edition of Words of Champions released yearly, each of which contained little over 3,000 words. Every year, about 550 words were rotated in and out of the list. It’s old but it’s definitely still relevant, and has plenty of very good words. I consolidated every word used in all 42 editions and put them in the files below. The hardest words from this list (Final and Intermediate) would probably show up as Regional Additional Words or in the earlier rounds at the national bee. At the very least, you should give them a look.
Thanks to the user Schola, who gave helpful information pertaining to this list in the comments!