THE man with the largest family in the United States is dead. Yesterday after-noon, at four o'clock, BRIGHAM YOUNG, the head of the Mormon Church, breathed his last. With him, perhaps, Mormonism in this country dies too. Certainly no one that he leaves behind is likely ever to ac-quire the power and influence that he has exercised. He succeeded the prophet JOSEPH SMITH in 1844, and in 1847 set-tled with his people in the Salt Lake val-ley and founded Salt Lake City. Converts in great numbers poured in from Europe, and the colony rapidly grew in wealth and importance. A State was formed in 1849 called Deseret, and a Legislature was elected and a constitution framed, but Congress refused to recognize this Govern-ment and proceeded to form the Territory of Utah. BRIGHAM YOUNG was appointed Governor of the new Territory by Presi-dent FILLMORE. Governor YOUNG soon drove the Federal Judges out of the Ter-ritory, and was accordingly displaced. Col. STEPTOE, of the United States army, was appointed to succeed him, but did not deem it prudent to accept the office, so that BRIGHAM in reality remained Governor. He declared that he would be Governor until the LORD AL-MIGHTY should remove him. President BUCHANAN sent a force of 2,500 men to Salt Lake city and appointed ALFRED CUMMING Governor, and though the Mor-mons had made preparations for resist-ance, an understanding was finally ar-rived at which ended hostilities. The Mountain Meadow massacre, with the de-tails of which ail newspaper readers are familiar, is believed to have been instigat-ed by YOUNG, and had not death removed him he would probably have been brought to trial and punishment. He was a man of great firmness. He obstinately fought all opposition, whether it sprang from his own church or whether it came from the United States authorities. He was never vanquished save by the nine-teenth Mrs. YOUNG, but he fought her long and well. A great leader is dead.