After their great success in the election of 1854, members of the American Party in Massachusetts found themselves, because of the secretiveness of their organization, with no clear public statement of party principles. In advance of a statewide meeting in Springfield in August 1855, Subordinate Council No. 5, the East Boston chapter of the American Party in Massachusetts, voted on a statement of party principles. These resolutions are found in the minutes of the Council, which are part of a collection of the Council's manuscript records held by the Massachusetts Historical Society.

The "Declaration of Principles" adopted in Springfield on 7 August 1855 differs substantially from the East Boston resolutions. It calls for even more vehement resistance to "any politico-ecclesiastical hierarchy" (i.e. Catholicism) and contains a much more explicit attack on the "slave power" in the United States.

The "Declaration of Principles" can be found on pages 2 and 3 of the Constitution of the State Council of the American Party of Massachusetts.