Which well-known American's pseudonyms have included Alice Addertongue, Harry Meanwell and Mrs. Silence Dogood?

All of these names were pseudonyms of Benjamin Franklin! Amazingly, he created Silence Dogood when he was 16 and did a convincing job of sounding like a 40-year-old widow. He crafted the letters to give his newspaper something juicy to publish to sell papers. His older brother still owned the printing press at the time and the rest of Philadelphia had no idea who Silence actually was. Silence even had two wedding proposals!

https://www.smithsonianmag.com/smart-news/benjamin-franklin-was-middle-aged-widow-named-silence-dogood-and-few-other-women-180961781/

A man I don't see enough of on my money: Benjamin Franklin.

He was was unable to get published under his own name in his brother's publication, New-England Courant so another pseudonym was born, Silence Dogwood.

https://en.wikipedia.org/wiki/Silence_Dogood

Franklin also wrote using in his pseudonym Richard Saunders in his own publication Poor Richard's Almanak.

https://en.wikipedia.org/wiki/Benjamin_Franklin