In the years following, similar bills were introduced and hearings were held to discuss the state of the environment and Congress's potential responses. In 1968, a joint House–Senate colloquium was convened by the chairmen of the Senate Committee on Interior and Insular Affairs, Senator Henry M. Jackson, and the House Committee on Science and Astronautics, Representative George P. Miller, to discuss the need for and means of implementing a national environmental policy. In the colloquium, some members of Congress expressed a continuing concern over federal agency actions affecting the environment.