Before Barack there was Sidney - America's most eligible and tolerable black men representing two generations. The kid from Bahamas who spent his teens in Miami, slept in New York city bus stations, became fluent in Russian(!) acts like a force of nature in one of his finest Hollywood performances in this film. Virgil Tibbs, the character Poitier plays in 'In the Heat of the Night' is ranked as one of the top 50 greatest performances by any actor.
It is an engrossing movie. There is the racial tension that flare up when a colored cop from a more liberal Northern state ventures into Sparta, Mississippi - a conservative white dominated Southern town in the fifties and sixties. Then there is the whole thriller part about who is the real murderer which the smart black cop, Virgil Tibbs tries to solve racing against time and luck. A must watch classic.