Four score and seven years ago, our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal - I think I got the quote right, but...
Now I am going to use the BLOCKQUOTE to indent this quote:

Four score and seven years ago, our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal.

Look at the difference in the way these look!
Now how about a quote within a quote type setup.

Four score and seven years ago, our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal.

Four score and seven years ago, our fathers brought forth on this continent a new nation, conceived in liberty and dedicated to the proposition that all men are created equal.

Note that the BLOCKQUOTE not only indents it also spaces around the quote.