Significantly? No, not at all. After the passage of The Civil Rights Act, I did notice people stopped using the “N” word in public and toned down their racist talk in public. But whenever white people observed people of different colors, they still made some snide comment or gesture.
Throughout the 70s, 80s and early in the 90s, I worked with a diverse team of designers and it was impossible not to notice that white people expressed their racism differently in New York, St. Louis, New Orleans, Los Angeles, Atlanta, Tallahassee, Miami, Nashville, Chicago, San Antonio, and Washington DC. Sometimes it was subtle, sometimes it was blatant and sometimes it was scary.
After working in Singapore, the contrast with the depth of racism in American culture really sunk in. Maybe you have to live in a place free of racism for a while, to actually see it in your own culture.
Most white people have never spent even one day of their lives as the only white person anywhere (not school, work, shopping, or even church). I suspect that is the reason, white people cannot see racism in themselves or the company they keep.
Erich, have you ever worked for someone, or lived somewhere where white people were the minority? If not, maybe that is why you and I differ on this issue.