On March 2, 1867, in response to the president's statements indicating that he planned to fire Cabinet secretaries who did not agree with him, Congress passed the Tenure of Office Act. The act required Senate approval for the firing of Cabinet members during the tenure of the president who appointed them. The Tenure of Office Act was immediately controversial; some senators doubted that it was constitutional and questioned whether the act's terms applied to Johnson, whose key Cabinet officers were Lincoln holdovers.