As anyone with even a smidgen of knowledge American history can tell you, our most famous pseudonym is Publius, the name used by James Madison, Alexander Hamilton and John Jay for The Federalist Papers, their articles published in newspapers urging adoption of the Constitution. The Anti-Federalists, too, used pseudonyms from Roman history such as Cato and Brutus.
Pseudonyms have long served writers whose voice would be otherwise suppressed or who, because of professional or political constraints, would not have been able to bring their thoughts to the public. Revolutionaries and political agitators often use pseudonyms. In the eighteenth century using pseudonyms was widely accepted in public political discourse. Among other virtues, it helps focus attention on the argument instead of the person advancing it. There’s been no shortage of scams perpetrated by people writing under real names, no shortage or grudge holders unwilling to leave their ill will at the discussion table, and no shortage of the small minded who seek to denigrate the messenger rather than engage the message.