What did the expression "Square Deal" refer to as used by Theodore Roosevelt in regard to the federal government?

The impact of Roosevelt's "Square Deal" was creating laws to workers and ending the child labor. He proposed that there should be laws regulating nation's food supplies. As a result of these actions the department of Labor and Commerce was created in 1903. and the the Pure Food and Drug Act was passed in 1906. Roosevelt's "Square Deal" meant that he would represent all interests impartially.