Carol, I forgot. Here are some quickie resources about the proclamation. In brief, though, the Executive Branch has no Constitutional power to make laws, only to enforce them. Presidential proclamations have been used ever since, usually for minor matters, but technically speaking law-making is the responsibility of the Legislative Branch.

Nor did the Emancipation Proclamation actually free any slaves. But it still turned the purpose of the war, and unlike many wartime promises, this one got lived up to with the 13th Amendment.

National Park Service -- text of proclamation and comments

Text of proclamation and more comments

More balanced commentary here