I can't seem to find any data regarding racial demographics at the US place (city) level for mayors and council members per year.
Is there any resources available with such information?
I would like to know and access them.
This would certainly be an interesting dataset to see, but as far as I am aware, municipal governments act in such silos with frequently changing leadership that there is no authoritative resource that breaks down the racial makeup of mayors and council members on an annual basis,.
That said, it is certainly a dataset that could be put together almost enitrely based upon 'Meet your Council' type pages on municipal wesites. That would take a while, though!
The City Mayors Foundation website has lists of current mayors for the largest cities in countries around the world. They also provide research, publishing & pro bono services:
The City Mayors Foundation maintains the City Mayors website, organises the bi-annual World Mayor Project and publishes original research. It also acts as a publishing house for its fellows. City Mayors also provides a range of pro bono services to local government, academic institutions, the press and members of the public.
They might have the data you're looking for, or at least be able to put you in touch with someone who does.