The role of the U.S. presidency has undergone several different phase changes throughout history. In the 1860's, following Lincoln's death, the country entered into a phase of congressional power; led by the Radical Republicans such as Thaddues Stevens and Charles Sumner. In the coming decades, most of the presidents were relatively weak in comparison to Congress. That all changed in the early 1900's, when Theodore Roosevelt ascended to the Presidency, following McKinley's assasination. Roosevelt became known to many historians as the "first modern President." T.R. (as he was often referred to) was not only a very powerful President but was the most popular since the days of George Washington. T.R.'s popularity allowed him to do things that other Presidents simply could not have gotten away with... for example, T.R. seized the Isthumus of Panama from Columbia (without a war declaration from Congress) with the intention of building the canal. T.R., in many ways, became the measuring stick for future presidents. This can be seen in presidents such as Wilson, and Franklin Roosevelt as they both became larger than life components to American life during there time.