From Reconstruction to 9/11. Which person, group, or event played the largest role in shaping the way in which we live today?
You might want to consider Reconstruction, Industrialization, the Progressive Era, the World Wars, the Great Depression, the liberalism of the 1960s, or the Reagan era, among others.
Talk about a broad question! There are probably thousands of possible answers to this one; but I'll focus on President Franklin Roosevelt and his administration. During the depression, when Roosevelt was first elected, the country was facing so many different problems that required many different ideas, notions, and programs to try to fix them. Many of these programs still have an effect of the country today... many of them are still in use. For one huge example, we can look to social security. Social security was meant to be a pension plan for elderly workers during the depression. The idea was to free up some jobs in the country for younger workers. At the same time, it was a way to help older Americans not work into their twilight years. Obviously, this was a huge change and had huge ramifications in the years that followed. Even still today, this single program is at the forefront of American politics. There are dozens of FDR's programs that are still alive and at work today... FDIC, the SEC, and on and on.