Answer :

Lincoln enforced equality in speech by mentioning the Declaration of Independence where human equality is mentioned, as well as by stating that the Civil War was going to be "a birth of a new freedom", which would give true equality to all American citizens. He also stated that the Civil War was not just a fight for the Union, but for the principle of human equality.
Lincoln equally mentioned democracy, by stating that the America's democracy needed to survive, "government of the people, by the people, for the people, shall not perish from the earth."
Lincoln stated liberty for all, mentioned above by his mentioning of equality as well as the Declaration of Independence, a symbol of the liberation of the states from the monarchy of Great Britain.