In a war, that demanded sacrifices from the American people in order for our troops and thereby the Allies to become victorious over the Axis forces, certain governmental laws were put into place to help effect such. It would seem that the intent of those laws was for the greater good of America, but in reality, the result of some of these laws, was in many aspects, the cheating of a fair wage for those that labored, and thereby more profit for those industries employing such.
For instance, the Stabilization Act of 1942 was enacted in October 2, 1942, so as to fix wages and salaries in order to preclude inflation during the World War. This meant in effect, that unions would no longer be able to negotiate for greater wages for their employees, nor would they be permitted to strike for such wage increases, but rather would have to settle for the pay that they were earning per the conditions of the Stabilization Act of 1942.
Not too surprisingly, in light of the fact that the Allies won the war, and that those that labored worked very hard and for long hours under stressful conditions and stagnant wages, all this good work was done in anticipation, that now that the world was safe for democracy -- that such a world would thereby require plenty of additional labor and work to rebuild what had been destroyed worldwide during that destructive war, and that America was well positioned to be the preeminent exporter of those goods and services, bar none. So that those that had been denied the benefits of union power, turned back to that power in order to receive what was their just due.
Unfortunately, a significant swath of those corporations, that were plenty busy during the war years, preferred to take the stance, that rather than share the good profits and growth to come, that they would not give in to labor and their wage demands, and hence strikes were initiated by petroleum workers, automobile workers, electrical workers, meatpackers, steel workers, and coal miners, in order to get what they had been denied during those war years, so as to be able to provide for their family and their future.
The labor strikes were effective, so effective in fact that the government threatened to seize the railroads and to utilize the army as strikebreakers in order to get the railroad workers to come to heel, which they subsequently did. So too, the congressional elections of 1946, changed the makeup of the Congress, so that they were able to thereby pass the Taft-Hartley Act which struck directly at the power of unions, in order for the government to have more power to control and to eviscerate the strength of unions, all essentially for the benefit of corporate power and corporate profits at the expense of the laboring class.
While labor unions, would continue to grow in numbers as well as in the percentage of the workforce so utilized, that was far more of a function of the aftermath of World War II, which was an era of strong economic growth and thereby vast economic benefits, but when that economic growth subsequently slowed down, it was the labor class that suffered the ill effects of such, for corporations recognized that offshore operations would allow them to utilize foreign labor at a much lower expense, thereby providing them with a far greater profit, and domestic unions had not the power to stop them.