American Protective Association 

"Loyalty to true Americanism, which knows neither birthplace, race, creed, or party, is the first requisite for membership in the American Protective Association." 

This is the number principle of the A.P.A., an organization founded in 1897 in Clinton, Iowa by Henry F. Bowers. The organization was an anti-Catholic and anti-immigrant secret society whose membership roles topped two million near the end of the 19th Century. Members were bound by oath to endeavor to exclude Catholics entirely from public offices. Propaganda was carried on by literature and lectures; forged documents were used, especially an alleged "papal bull" calling for a massacre of Protestants. Capital was made out of the coming of Monsignor Satolli, papal delegate, and also out of the parochial-school question. Few prominent men acknowledged membership. It was associated with the Republican party, and a great source of vexation to it. In failing to prevent the nomination of William McKinley (1896) and also to secure representation in the Republican platform for some principles of the order, its prestige received a blow from which it never recovered.

Bowers was a Mason, and he drew from its fraternal ritual—elaborate regalia, initiation ceremonies, and a secret oath—in organizing the A.P.A.. He also drew many Masons, an organization that barred Catholics. The organization quickly acquired an anti-union cast. Among other things, the A.P.A. claimed that the Catholic leader of the Knights, Terence V. Powderly, was part of a larger conspiracy against American institutions. Even so, the A.P.A. successfully recruited significant numbers of disaffected trade unionists in an era of economic hard times and the collapse of the Knights of Labor. This secret oath taken by members of the American Protective Association in the 1890s revealed the depth of Protestant distrust and fear of Catholics holding public office.
 

The A.P.A. oath:

I do most solemnly promise and swear that I will always, to the utmost of my ability, labor, plead and wage a continuous warfare against ignorance and fanaticism; that I will use my utmost power to strike the shackles and chains of blind obedience to the Roman Catholic church from the hampered and bound consciences of a priest-ridden and church-oppressed people; that I will never allow any one, a member of the Roman Catholic church, to become a member of this order, I knowing him to be such; that I will use my influence to promote the interest of all Protestants everywhere in the world that I may be; that I will not employ a Roman Catholic in any capacity if I can procure the services of a Protestant.

I furthermore promise and swear that I will not aid in building or maintaining, by my resources, any Roman Catholic church or institution of their sect or creed whatsoever, but will do all in my power to retard and break down the power of the Pope, in this country or any other; that I will not enter into any controversy with a Roman Catholic upon the subject of this order, nor will I enter into any agreement with a Roman Catholic to strike or create a disturbance whereby the Catholic employes may undermine and substitute their Protestant co-workers; that in all grievances I will seek only Protestants and counsel with them to the exclusion of all Roman Catholics, and will not make known to them anything of any nature matured at such conferences.

I furthermore promise and swear that I will not countenance the nomination, in any caucus or convention, of a Roman Catholic for any office in the gift of the American people, and that I will not vote for, or counsel others to vote for, any Roman Catholic, but will vote only for a Protestant, so far as may lie in my power. Should there be two Roman Catholics on opposite tickets, I will erase the name on the ticket I vote; that I will at all times endeavor to place the political positions of this government in the hands of Protestants, to the entire exclusion of the Roman Catholic church, of the members thereof, and the mandate of the Pope.

To all of which I do most solemnly promise and swear, so help me God. Amen.