Historically speaking, voters prefer a person with experience in the Executive branch of Government or a military background. This is why previous and sitting State Governors and men with military leadership experience have fared better in elections such as George Bush and Eisenhower.
There have been quite a number of presidents who had served in Congress at some point however only 3 Senators have been able to move from Congress to the White House. This is because voters prefer that they gain executive experience first like Truman and James Monroe did as Vice President and Secretary of State respectively.
the Emancipation Proclamation officially took effect, the ideals of the Proclamation had been carefully contemplated by President Lincoln many months before.
