The UK industrialized first.
From an interview with EurActiv:
EurActiv: Who is most responsible for climate change – all of us equally or are some people more responsible than others?
Hansen: For fossil fuels use we have very good statistics. The US is responsible for 26% of the excess CO2 in the atmosphere, and China for 10%. The parts of the world that industrialised first are most responsible. The UK is number one, the US is number two and Germany is third.