She was a conservative activist and founder of the Eagle Forum, which campaigned against the Equal Rights Amendment (ERA). The letter was addressed to the leaders of the ERA ratification campaigns in the states, effectively halting their efforts.
While the letter's official authorship was attributed to Schlafly as the National Chairman of "STOP ERA," it's important to note that the entire campaign was orchestrated and spearheaded by her. This letter marked a significant victory in her fight against the ERA, which ultimately failed to be ratified.