Which of the following was an innovation of World War I?

Had Lincoln lived, it is likely that:

The two-way transfer of plants, animals, and diseases between Europe and the Americas was known as the:

The lynching of African Americans in the South:

The first permanent English settlement in North America was: 

Radical Republicans understood that essential to maintaining their control of Congress was:

Thomas Paine’s pamphlet, Common Sense, is significant because it:

The Boston Massacre: 

Methods of disenfranchising voters included all of the following EXCEPT:

Why was the formation of labor unions a consequence of industrialization in the late 1800s?