The member of the Big Four that never joined the Leaque of Nations was?

Question

The member of the Big Four that never joined the Leaque of Nations was?

Answer 1

The United States, because the prevailing undercurrent against foreign entanglements in the country motivated enough voters (who in turn motivated enough lawmakers) to refuse to participate in what they saw as European in origin anyway.  

Support in the United States was virtually divided among party lines -- Wilson, the President and Democrat was for it with most of his party, and the Republican-controlled Senate (which constitutionally has the power to make treaties) was not.

Great Britain, France, and Italy of the Big Four DID join the League, but they'd also been involved in all of World War One (since 1914) -- the United States didn't enter the war for another three years.

Answer 2

The United States never officially joined the League of Nations