Laki's list seems roughly on par with what I'd say. Though I would argue a bit on the German Empire being the most powerful worldwide from 1870-1914. Still seems like it's the limeys to me.
Yeah I don't really buy Germany overtaking Britain at any point, but you could make a compelling case the post-Civil War US took the lead earlier than 1914.
The US certainly had the largest economy by the late 19th century, though it is complicated depending on how you count the India. WWI pushed the US far enough into the lead GDP wise to be larger than the combined strength, but if counted separately, the US was ahead as far back as 1879.
I seem to recall reading at some point that Britain didn't recover very well from the panic of 1873 either.
