I am no literary in this subject but here are my thoughts:



Untouchability was defied from time and on. If you read the life of adi
Shankaracharaya you will find that untouchability was defied by lord
Shiva himself.



I cannot vouch for manushmriti but my understanding is that the laws
that were made by using manushmriti is where the problem is. During the
old times laws were made by the almighty kings and were forced into the
society and no one could denounce it if it had the support of the royal
nobles.



I had a long discussion about manushmriti with few scholars from time
and on and here is what they have is the exert of the discussion. Caste
is not determined by birth rather by deeds. ब्रह्म जानाती ब्राह्मण्
(Brahma janati Brahmana) which means if you know ब्रह्म (God) than you
are a brahmin. One who cleans garbage is sudra, one who fights and
protects is chetreya etc.



Once I had discussion with an Indian historian/scholar about the same subject and
he said that there was no discrimination in ancient India for education
or higher education. If you read ancient history this will become clear.



I agree with you and I don't understand why manushmriti is so harsh on
other casts, my guess is it is politicized like any other religious
text and have added discrimination for the benefit of the few.



On the same note US is trying hard to fight discrimination but there is
a section for "race" in every form that you have to fill it in
including government, credit card, bank and university forms. No one
can deny that there is racism in US even though there are laws against
it and discrimination is increasing despite all the efforts. US is
facing the problem of discrimination like we are facing.



My 2 cents.