Which technological development led to an increased demand for slaves in the United States during the early - to mid-1800s? A) the steel plow B) the cotton gin C) the mechanical reaper D) the combine harvester

B) The cotton gin was a technological development led to an increased demand for slaves in the United States during the early to mid 1800s. This invention made it easier to separate the seeds from cotton and thus process more cotton quickly. This increased the size of cotton farms and also increased the demand for slave labor.