There is a lot of information on these topics. To help you organize it, let's think of them by type:
1. Online Encyclopedias
2. eBooks
3. Articles in databases
4. Quality online sources
All of these can be found online and through http://nclive.org, here's how:
1. Encyclopedias
Funk and Wagnalls Encyclopedia: http://nclive.org/browse/homeworkhelp
Student Research Center: http://nclive.org/browse/homeworkhelp
Both of these will give you broad articles on your topics that will be helpful.
All of the topics can be searched with their names, for example, "holocaust", "civil rights movement", etc., except for Native American disenfranchisment. For that topic, search "Native Americans and voting".
2. Books and eBooks
eBooks (online books) are available here: http://nclive.org/browse/ebooks. When you find a title you like, try to choose "view epub" or "view full text"
Video tutorial on downloading ebooks here: http://youtu.be/7vyEEi4yAik
3. Articles in Databases
Articles tend to be shorter than books and focused on more specific aspects of the topic. If they are too broad, go back and use books and encyclopedias.
Student Research Center: http://nclive.org/browse/homeworkhelp
MAS Complete: http://nclive.org/browse/homeworkhelp : this has magazine articles and primary sources such as speeches and texts.
Masterfile Complete: http://nclive.org/browse#m : Be sure to click full text only. 
4. Quality Online Sources
It is possible to find quality online sources for these topics. Of course, many online sources are not reliable. Here are some tips.
* add "site:.gov" to your search to get government websites on these topics. For instance...
The government has a lot of valuable information on these historical topics, including information from museums like the Smithsonian, United States Memorial Holocaust Museum and others.
More Help
If you need more help, please ask NCknows. If you are in a class, try to take turns so we can provide the best service.