They supported by ensuring that those workers would get higher pay, as well as promising that the state would in turn help the company once the war is over. It was like the war bonds thing but more complex as it involved companies and not regular people.
If it is written down, it's called "libel" whereas if it's spoken, it's called "slander." Defamation law attempts to balance the freedom of speech and open exchange of ideas without giving someone permission to run around spreading lies about another that may harm his or her reputation, ability to earn a living, etc.
It was supposed to prevent the export of cotton and smuggling of war materials into the confederacy. The confederacy constructed torpedo boats to try and get around it.
