Answer:
To find out the answer to this question, it is necessary to know beforehand who took part in The Federalist Papers and which was their pseudonym.
And, its members (of The Federalist Papers) were Alexander Hamilton, James Madison, and John Jay, all of them under the pseudonym of "Publius". Also, as quite important information, The Federalists Papers itself is more of a collection of eighty-five articles and essays.
Now, why did they use a pseudonym? Well, it was mostly because (around those times) it used to be common to publish articles under pseudonyms since it was believed that it helped the reader focus on the quality of the arguments rather than getting "sidetracked" on the reputation (of the arguer.)
Explanation:
Hello, I hope this helps, to answer your question I based myself on a comment found on a website named "Quora"
credits to a person whose account is named as "Ken Fishkin", he talked a few more lines about this, and provided a quote as well, if you need more Infomation you might want to check that out.
Either way feel free to remove also any information you may not need, again hope this helps!