<span>the spread of television ownership to most American households</span>
I think it is Earthquakes
The conventions came into being after 1830 are:Colored conventions- which are series of convention held in national and regional level after the american civil war. it was attended by politician, businessman, religious leaders, writers and publishers.
Virginia Constitutional Convention
National Negro Convention Movement
Hope this helps.
The steam locomotive allowed for the transportation of goods at a much more rapid rate than by horse. The railroad let people know exactly where and when goods would arrive. The trains also gave the cargo a safer ride as it was much more difficult to rob a train than a horse drawn transport. As more railroads were built, products could travel farther than ever before in a timely manner. This brought down the cost of freight transport and increased profits for many businesses.
Child labor and massive amounts of air pollution.
