Types of Graphs. 1  Types of Graphs: Bar Graphs. 2  Types of Graphs: Box and Whiskers (Boxplots) 3  Types of Graphs: Frequency Distributions.  Types of Graphs: 1  Histogram. Types of Graphs: Line Graphs.  Types of Graphs: Pie 1  Graphs. Types of Graphs: Scatter Graphs.  Types of Graphs: Stemplots.
The 1950s. By the end of the war, TVA had completed a 652-mile navigation channel the length of the Tennessee River, and had become the nationâs largest electricity supplier.
Soon the demand for electricity was outstripping TVAâs capacity to produce power from hydroelectric dams. As a result, TVA began building coal-fired steam plants, and by 1955, coal surpassed hydropower as the systemâs primary power source.