Imagine a deck about 20 feet wide, and perhaps 120 feet long, and 5 feet high.
Imagine this to be the place of abode and sleep during long, hot, healthless nights of 720 human beings! At sundown, when they were carried below, trained slaves received the poor wretches one by one, and laying each creature on his side in the wings, packed the next against him, and the next, and the next, and so on, till like so many spoons packed away they fitted into each other a living mass.

Just as they were packed so must they remain, for the pressure prevented any movement or the turning of hand or foot, until the next morning, when from their terrible night of horror they were brought on deck once more, weak and worn and sick." Then, after all had come up and been splashed with salt water from the pumps, men went below to bring up the dead.

There was never a morning search of this sort that was fruitless.

The stench, the suffocation, the confinement, oftentimes the violence of a neighbor, brought to every dawn its tale, of corpses, and with scant gentleness all were brought up and thrown over the side to the waiting sharks.

The officer who had this experience writes also that it was thirty days after capturing the slaver before he could land his helpless charges.
No great moral evil can long continue when the attention of men has been called to it, and when their consciences, benumbed by habit, have been aroused to appreciation of the fact that it is an evil.