Question

They had real concerns because they were afraid that when people started to move into the new land, and because slavery was still active, the slave states would have more power because they would have more representatives than the other states.

Answer 1

Slavery had been around for a while and was still going on when people started moving onto new land without slavery. However, the states that had slavery seemed more powerful because there were more representatives, so this worried people moving to the new places.