Over speculation means to over "guess." eg, majority of the people feel the stock market will go up, so they greedily buy, when in reality it's the peak already and stock market prices will drop soon.
There were many actions and characteristics of Teddy Roosevelt that contributed to his reputation as the first modern president, but one of the biggest was that his set aside land for national parks.
This would be known as the "judicial branch" of government, and the courts that are created by Congress are designated as the "lower courts," since the Founders wanted this to be a more democratic process.
