The correct answer is:
Competition from freedmen
The Labor Crisis worsened for the poor whites throughout the 1840s, right on the heels of the economic recession, as over 800,000 slaves poured into the Deep South, displacing unskilled and semi-skilled white laborers. By this time, the profitability and profusion of plantation slavery had rendered most low-skilled white workers superfluous, except during the bottleneck seasons of planting and harvest.