A cog in the New York party machine, upon his presidency, Chester Alan Arthur revealed an unanticipated integrity and honesty. He helped reform the civil service, prosecuted corruption in the post office and attempted to lower tariffs. He protected Chinese Americans by vetoing a law that threatened a ban on their immigration. By the end of his term, Mark Twain decided, "it would be hard to better President Arthur's administration." Learn more with this biography from American Experience: "The Presidents."