Executive Order 9066 and how did it affect civil liberties in the United States?

Executive Order 9066 was issued in February, 1942, by President Franklin D. Roosevelt. The order allowed the Secretary of War to designate certain areas as military zones. FDR's order cleared the way for relocating tens of thousands of Japanese Americans into to internment camps. The civil liberties of those persons were taken away by Executive Order 9066. Rounding up Japanese Americans and confining them in camps, without any due process, was later recognized as an unconstitutional action.

Further explanation:

As for the effect of Executive Order 9066 on civil liberties, in 1976, President Gerald Ford issued a strong statement about that. He rescinded the old executive order, which was still on the books. In his proclamation, President Ford said:

We now know what we should have known then--not only was that evacuation wrong, but Japanese-Americans were and are loyal Americans ... I call upon the American people to affirm with me this American Promise - - that we have learned from the tragedy of that long-ago experience forever to treasure liberty and justice for each individual American, and resolve that this kind of action shall never again be repeated.