<span>i think is this one -adoption of a social caste system </span>
<span> Madeira and the Canary Islands </span>
The answer for this is "Compromise of 1850".
The Compromise of 1850 is a set of laws dealing with the issue of slavery. California was admitted as a free state, upsetting the groups in favor of slavery and satisfying those opposing it in the U.S senate. In Addition, California abolished the slave trade by entering the Union as a free (no slavery) state.
a central data hub for a "smart"city
