In the beginning of the last year, when its present proprietors assumed control of the Knickerbocker, they announced their determination to spare no pains to place it in its true position as the leading _literary_ Monthly in America. When rebellion had raised a successful front, and its armies threatened the very existence of the Republic, it was impossible to permit a magazine, which in its circulation reached the best intellects in the land, to remain insensible or indifferent to the dangers which threatened the Union. The proprietors accordingly gave notice, that it would present in its pages, forcible expositions with regard to the great question of the times,--_how to preserve the_ UNITED STATES OF AMERICA _in their integrity and unity_. How far this pledge has been redeemed the public must judge. It would, however, be mere affectation to ignore the seal approbation which has been placed on these efforts. The proprietors gratefully acknowledge this, and it has led them to embark in a fresh undertaking, as already announced,--the publication of the CONTINENTAL MONTHLY, devoted to Literature and National Policy; in which magazine, those who have sympathized with the political opinions recently set forth in the KNICKERBOCKER, will find the same views more fully enforced and maintained by the ablest and most energetic minds in America. The KNICKERBOCKER, while it will continue firmly pledged to the cause of the Union, will henceforth be more earnestly devoted to literature, and will leave no effort untried to attain the highest excellence in those departments of letters which it has adopted as specialties. The January number commences its thirtieth year. With such antecedents as it possesses, it seems unnecessary to make any especial pledges as to its future, but it may not be amiss to say that it will be the aim of its conductors to make it more and more deserving of the liberal support it has hitherto received. The same eminent writers who have contributed to it during the past year will continue to enrich its pages, and in addition, contributions will appear from others of the highest reputation, as well as from many rising authors. While it will, as heretofore, cultivate the genial and humorous, it will also pay assiduous attention to the higher departments of art and letters, and give fresh and spirited articles on such biographical, historical, scientific, and general subjects as are of especial interest to the public. In the January issue will commence a series of papers by CHARLES GODFREY LELAND, entitled "SUNSHINE IN LETTERS," which will be found interesting to scholars as well as to the general reader, and in an early number will appear the first chapters of a NEW and INTERESTING NOVEL, descriptive of American life and character.