Arduino Uno Serial Problems (57600 baud is broken)

What are you using to communicate with your Arduino? Are you using the built-in serial monitor? Whatever you are using, you must make sure to set its baud rate to match whatever you give to Serial.begin(). It sounds like you are changing the baud rate in your sketch but not in the serial monitor.

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The Quick Shield: breakout all 28 pins to quick-connect terminals