Aside from Montana, the remaining 49 are “at will” employment states. You can be fired for any reason at any time, aside from if your employment is terminated for being part of a protected class, regardless of if you are a contractor or not. There are some jobs that have more protections, like union jobs (yay unions). There are also some employment agreements that are not at will if I believe too.
You can also leave your job at any time for any reason in an at will state.
Portable monitors have been extremely convenient when I used to travel to a client site to program. A cheap one is worth getting.