While pioneers from Virginia and North Carolina were moving into Kentucky and Tennessee, emigrants from the Northern States were moving into western New York, or were crossing the Alleghanies and settling the upper valleys of the Ohio. The settlement of western Pennsylvania began even before the Revolution. In 1770 Washington revisited the scenes of his early youth and found Pittsburgh a village of twenty houses. Fourteen years later he would have found it a town of two hundred houses and a thousand inhabitants. Western Pennsylvania filled rapidly with settlers, and soon pioneers began to float down the Ohio in flatboats and build their homes on the soil of the Northwest Territory. In a few years so many white people were living in this Western domain that it became necessary for them to have some form of government. So Congress (in 1787) passed the law known as the Ordinance of 1787, the most important law ever passed by a lawmaking body in America. [Illustration: Emigrants descending the Tennessee River.] The great law of 1787 provided that, as the Northwest Territory filled up with people, it should be divided into States--not fewer than three and not more than five. Each State was to be governed according to the will of its voters; there was to be no slavery; religious liberty was guaranteed; education was to be encouraged; Indians were to be justly treated. When a community came to have as many as 60,000 inhabitants it was to be admitted into the Union as a State, with all the rights of the older States; during the time in which a community was too small for statehood it was to be governed as a Territory. Such were the provisions of the Ordinance of 1787. The law breathed the spirit of freedom, and showed plainly that Western settlers could look forward to fair treatment at the hands of the national government. The Western communities were not to be dependent colonies; they were to be self-governing States. THE BEGINNINGS OF OHIO. The first community to be built up in the Northwest Territory was Ohio. In 1788 a party of forty-eight New Englanders, the Pilgrim Fathers of Ohio, landed at the mouth of the Muskingum in a bullet-proof barge which bore the historic name of _Mayflower_. It was well that the barge was bullet-proof, for white men passing down the Ohio in boats were in constant danger of being shot by Indians lurking along the shore. The _Mayflower_ party went ashore opposite Fort Harmar, where there was a regiment of soldiers. In the winning of Ohio, soldiers and settlers went hand in hand, for everywhere through the Northwest there were Indians, and every acre of land won by the ax and plow had to be guarded and defended by the rifle.