...There can be no divided allegiance here. Any man who says he is an
American, but something else also, isn't an American at all. We have
room for but one flag, the American flag, and this excludes the red
flag, which symbolizes all wars against liberty and civilization, just
as much as it excludes any foreign flag of a nation to which we are
hostile...
- Theodore Roosevelt's letter, 1919
(sources: http://www.cnn.com/2006/US/03/27/quote.roosevelt/index.html, http://www.snopes.com/politics/graphics/troosevelt.pdf)
I believe this somehow encouraged the immature effect on the simple minded, easily jealous racists.
Although, the notion against Hyphenated American was noble, waking those who think their dual nationalities status is an excuse to escape from social responsibility, the lack of constant discretion on the subject has easily turned the outcome negatively.
Of course, I came across this through the today in History Channel of NY1.com where Roosevelt made the announcement in NYC on Oct 12 (then Columbus Day) in Carnegie Hall:
"There is no room in this country for hyphenated Americanism. When I
refer to hyphenated Americans, I do not refer to naturalized Americans.
Some of the very best Americans I have ever known were naturalized
Americans, Americans born abroad. But a hyphenated American is not an
American at all... The one absolutely certain way of bringing this
nation to ruin, of preventing all possibility of its continuing to be a
nation at all, would be to permit it to become a tangle of squabbling
nationalities, an intricate knot of German-Americans, Irish-Americans,
English-Americans, French-Americans, Scandinavian-Americans or
Italian-Americans, each preserving its separate nationality, each at
heart feeling more sympathy with Europeans of that nationality, than
with the other citizens of the American Republic... There is no such
thing as a hyphenated American who is a good American. The only man who
is a good American is the man who is an American and nothing else."