Can the U.S. Supreme Court declare a federal law unconstitutional and void it?

The Industrial Revolution led to imperialism in Africa in the mid-1800s; the 1st Euro's to explore the interior of Africa were missionaries & explorers; reports of large deposits of natural resources & the rise of nationalism in Europe set off a race for African colonies. Europeans introduced new technologies like railroads, telegraph lines, & steamboats...but transportation routes only connected areas that benefited European businessman; Europeans brought an end to the slave trade but Africans were paid low wages & exploited. Europeans built schools, churches, & hospitals...but Africans were taught European culture; Europeans profited off Africa's raw materials & cheap African labor; Africans were unable to rule themselves, participate in voting, or learn professional skills