What marked the end of the frontier?
a. when native americans took all of the land
b. after settlers completed the gold rush
c. when fences went up and open land was gone
d. when people stopped settling
e. when treaties signed over land

"d. when people stopped settling" would be the best option for the marker of the frontier land in the United States but there was and still is lots of open territory. 

Economic success prussia had a very strong economy, partly due to the success of the zollverein. stronger prussian army king wilhelm wanted to build a bigger, stronger army but was blocked by the prussian landtag (parliament).-credits to google for putting answer -credits to slideshare for making answer-credits to me for putting answer on brain.ly