3 The frontier was about to close and the safety valve was ceasing to operate, a reexamination of life began Beneath the glittering surface of prospective there lay suffering and unhappiness, Disillusionment and rustration were widely felt 3The age of Romanticism and Transcendentalism was by and large over. Meanwhile younger writers appeared on the scene, such as William Dean Howells, Henry James, Mark Twain, and so on, which means the coming of new literary age, American realism 退出3) The frontier was about to close and the safety valve was ceasing to operate, a reexamination of life began. Beneath the glittering surface of prospective there lay suffering and unhappiness, Disillusionment and frustration were widely felt. 3) The age of Romanticism and Transcendentalism was by and large over. Meanwhile younger writers appeared on the scene, such as William Dean Howells, Henry James, Mark Twain, and so on, which means the coming of new literary age, American realism. 退出