With the Great Upheaval, which began in 1884, and the inrushing of hundreds of thousands of semi-skilled and unskilled workers into the Order, a new situation was created. The leaders of the Knights realized that mere numbers were not sufficient to defeat the employers and that control over the skilled, and consequently the more strategic occupations, was required before the unskilled and semi-skilled could expect to march to victory. Hence, parallel to the tremendous growth of the Knights in 1886, there was a constantly growing effort to absorb the existing trade unions for the purpose of making them subservient to the interests of the less skilled elements. It was mainly that which produced the bitter conflict between the Knights and the trade unions during 1886 and 1887. Neither the jealousy aroused by the success of the unions nor the opposite aims of labor solidarity and trade separatism gives an adequate explanation of this conflict. The one, of course, aggravated the situation by introducing a feeling of personal bitterness, and the other furnished an appealing argument to each side. But the struggle was one between groups within the working class, in which the small but more skilled group fought for independence of the larger but weaker group of the unskilled and semi-skilled. The skilled men stood for the right to use their advantage of skill and efficient organization in order to wrest the maximum amount of concessions for themselves. The Knights of Labor endeavored to annex the skilled men in order that the advantage from their exceptional fighting strength might lift up the unskilled and semi-skilled. From the point of view of a struggle between principles, this was indeed a clash between the principle of solidarity of labor and that of trade separatism, but, in reality, each of the principles reflected only the special interest of a certain portion of the working class. Just as the trade unions, when they fought for trade autonomy, really refused to consider the unskilled men, so the Knights of Labor overlooked the fact that their scheme would retard the progress of the skilled trades.