The growing improvement of nationalism in 19th centrury Europe

I'm wondering if you meant to say "the growing impact of nationalism in 19th century Europe." Whether the growing emphasis on nationalism was an "improvement" or not would be very much a matter of debate! As people groups in Europe became more conscience of their "national" identity - - that is, having to do with race, language, ethnicity, culture, and such - - they became more and more competitive with one another and saw each other as rivals or enemies. As nationalist fervor grew and grew, it spilled over into imperialism as the nations of Europe competed for power abroad. And eventually it gave rise to the tensions that led to horrific wars between European nations - - World Wars I and II.