Verb: revoke or annul (a law or congressional act).
Noun: the action of revoking or annulling a law or congressional act.
        
                    
             
        
        
        
The development of railroads was one of the most important phenomena of the Industrial Revolution. Trains provided supplies and equipment and a lifeline of the army. Trains made a big impact on the citizens.  Railroads were visible symbols of industry and modernity during the Civil War.
 
        
             
        
        
        
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the preservation of the Union and his early opposition to slavery
 
        
             
        
        
        
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It changed the way we think and made the modern age possible.