On occasion I've found that there are programs set up for bringing people of particular ethnicity or technical skills into the US.
Is there a way to find what programs like this are currently in effect?
Yes. It is called "INA" - Immigration and Nationality Act. You can find it in any legal library (including virtual ones). It is also available freely on the USCIS website.
Specifically you probably want to read Chapters 1 and 2 of Title II of the act.
In the US, all the immigration and admission classes and categories are coded in statute, so you just need to read it.