 Again, disasters and high loss of life prompted congressional action through the passage of the Act of February 28, 1871.A showboat (or show boat) was a form of theater that traveled along the waterways of the United States, especially along the Mississippi and Ohio rivers.A showboat was basically a barge that resembled a long, flat-roofed house, and in order to move down the river, it was pushed by a small tugboat (misleadingly labeled a towboat) which was attached to it.