The Blob (1958)

Setting: Small town America; contemporary

Giant unstoppable mound of red gel consumes all human life it touches. A metaphor for creeping Soviet expansionism perhaps? Interestingly the solution is containment via a cold war (CO2 fire extinguishers can subdue the best). Of course it was up against all American Steve McQueen, so it never had much of chance. This is what a Jerry Wald produced monster movie might have looked like.