"Our labor unions are not narrow, self-seeking groups. They have raised wages, shortened hours and provided supplemental benefits. Through collective bargaining and grievance procedures, they have brought justice and democracy to the shop floor."
JOHN F. KENNEDY, speech, Aug. 30, 1960
"The labor movement did not diminish the strength of the nation but enlarged it. By raising the living standards of millions, labor miraculously created a market for industry and lifted the whole nation to undreamed of levels of production. Those who attack labor forget these simple truths, but history remembers them."
MARTIN LUTHER KING, JR., speech to AFL-CIO, Dec. 11, 1961 http://www.notable-quotes.com/l/labor_unions_quotes.html#GWslH3R6MqO5UKsK.99
Let me know if you want a more detailed answer, which would probably be more appropriate in the Politics forum. Suffice it to say that unions are about much more than striking.