Poll taxes means you have to pay a tax before allowed to vote. That's a way of preventing poor persons (like blacks in the South) from voting.
In addition to poll taxes, other measures were also used to block blacks from participating in the voting process. For instance, literacy tests would require persons to pass certain standards of reading and writing in order to qualify for voting. These tests were aimed at blacks, who had not had access to the same education as whites.
When the United States annexed Texas in 1845 and made it a new American state, the United States also inherited a long-smoldering border dispute between the breakaway Texans and the government of Mexico.
The main way in which the causes of the enlightenment were similar to the causes of the industrial revolution was that both focusses on the "common man" instead of the elite.
