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  The election would ultimately be awarded to William McKinley and Theodore Roosevelt.
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  The election would ultimately be awarded to Theodore Roosevelt and Charles W. Fairbanks.
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  The election would ultimately be awarded to William Howard Taft and James S. Sherman.
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  The election would ultimately be awarded to Woodrow Wilson and Thomas R. Marshall.
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  The 16th Amendment introduced an income tax.
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  The 17th Amendment allowed popular election for U.S. Senators.
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  The election would ultimately be awarded to Woodrow Wilson and Thomas R. Marshall.
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  The 18th Amendment established prohibition.
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  The 19th Amendment allowed women to vote in elections.
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  The election would ultimately be awarded to Warren G. Harding and Calvin Coolidge.