The most important event of 1861 was the outbreak of the Civil War in America, when the invention of the American Constitution was put to its severest test. It had been known ever since the adoption of the Constitution that the instrument was faulty in not defining clearly the relative rights of the Federal Government and the separate states; but it had been found impossible to secure the assent of a sufficiently large body of citizens to any proposition that defined them clearly; and so the machine of Government had operated for nearly three-quarters of a century, with the disquieting knowledge in the minds of its operators that conditions might put it to a test that would break it down, and perhaps destroy it totally. The most dangerous condition was seen to be the one associated with the question of slavery in the Southern States. This question, and the consequent condition of antagonism between the North and the South, became rapidly worse during the period from 1846 to 1861, when war between them finally broke out. The war was ultimately decided in favor of the North, despite the fact that the South was much the better prepared; in fact, that the North was wholly unprepared. The main weakness in the Confederate situation was the fact that cotton was virtually the only product with which she could raise money for feeding and equipping her army, that she had to get the equipments from Europe, and that the line of communication to Europe was across the Atlantic Ocean, 3000 miles wide. The weakness seemed, during a period of about twenty-four hours, to be removed by the invention of the iron-clad _Merrimac_; for the _Merrimac_ destroyed the _Cumberland_ and _Congress_, two of the finest warships on the Union side, without the slightest difficulty in one forenoon, and threatened the destruction of all the other Union ships. The Union ships having been destroyed or made to flee to port, complete freedom from blockade of the Confederate coast would follow immediately. The _Monitor_ had been invented years before; but no steps had been taken to build her, despite the insistence of the great inventing engineer, John Ericsson. News of the work of constructing the _Merrimac_ had reached the North, however, and stimulated the northern imagination to the extent that it was able to see in the _Monitor_ a savior (and the only savior) from the _Merrimac_. By the exercise of amazing engineering skill, Ericsson constructed his invention with such speed and precision that the _Monitor_ was able to meet and defeat the _Merrimac_ the very day after she had destroyed the Union ships.