All past tenses gravitate towards -ed...In my memory I think the conjugation I favor is: I plead, I pled, I have pleaded... but both the American Heritage and the Websters have pleaded or pled as the past tense/past participle.
Aha! A grammarian in the midst of us. Thanks, Knitting. I had the same question about pled/pleaded.
Thanks for the replies to my question in post #19.