Many prospective law students begin thinking about law school in high school (or even earlier). Having said this, these dreams about law school seem to become more real when these students apply to college. They begin thinking about whether some of their decisions (most notably, the school they attend and their undergraduate major) will impact their odds when applying to law school down the road.
I think it's safe to say that a student's choice of college and undergraduate major will have some effect as he or she prepares for and applies to law school. Having said this, it’s difficult to say the exact amount of influence that they may have on students' law school applications.
When applying to law school, admissions officers will look most closely at your LSAT score and your undergraduate GPA. As part of their review of your GPA, they will look at the courses that you took and the school that you attended. As a starting point, admissions officers could be more impressed if you attended a “prestigious” school like Harvard compared to a smaller state school. There may be some exceptions to this general principle, however. Some that come to mind are if you faced significant hardship in your life and attended a “less prestigious” school, if you’re the first in your family to attend college (wherever it is), or if you received a well-renowned scholarship at a lower ranked school. By referencing some of these circumstances in your personal statement, you may be able to differentiate yourself from other similarly situated candidates.
So my answer to whether your college selection and undergraduate major will affect your application is the stereotypical law school answer: “it depends.” My advice would be to attend the school where you feel most comfortable, regardless of whether it’s highly ranked or considered “prestigious.” Also, take into account your financial situation and the extent to which you’ll have to take our undergraduate loans. As far as your actual courses or major, I’d highly recommend that you pursue topics that interest you, rather than gaming the system and selecting easier courses to obtain a high GPA for the purpose of law school admissions. Plus, you may discover in college that you may not actually want to go to law school.
All in all, your college and undergraduate major has some effect, but not nearly as much doing well in your courses (whatever they are) and doing well on the LSAT. If you’re interested in law school, I would focus on these two things.