Check out this 8th grade civics test from 1957. This is a time capsule, it is. Most of the comments focus on how badly public education has degenerated since. Although test scores in math and science would doubtlessly back that up, I don't buy this particular test as further evidence of the slide.
One could certainly argue that a child's being able to rotely recite the Supreme Court justices served little purpose in 1954, but it would be positively bereft of purpose in the Age of Google. This was never more clear than when 23 year-old Darcy and I discussed the differences in our educations. Among other glorious details, I knew that Lake Superior is the largest great lake. She did not and never did.
"Why the hell would I ever need to know that?" she asked, incredulous that I still had that useless bit of 8th grade Social Studies memorized, lo these many years later. "And even if I did, I could find it in, like, two seconds."
To summarize: we might be dumber now, but we can afford to be.