weapons and articles used for fighting
Many Northerners were happy that free states now had more representatives in Congress. However, many were also upset with the Fugitive Slave law.
This law, that was part of the Compromise of 1850, made it so that any slave that escaped to the North must be returned to their owner in the South. Many northerners thought this was unfair and did not want to follow this law. This is because almost all northern states had outlawed slavery by this point and time.
What did the planes have in common? they were all domestic flights heading towards the West coast, which means that they would have a great amount of fuel on them: this would increase the explosion and fire after the crashes. This was a likely reason for those and not other planes being chosen.
Obviously the poor had no money, so the bosses of say New York would pay clueless immigrants to vote for them in elections to keep them in high city offices and to continue holding power.