What major events led to the devolution of the second party system

As late as 1850, the two-party system seemed healthy. Democrats and Whigs drew strength in all parts of the country. Then, in the early 1850s, the two-party system began to disintegrate in response to massive foreign immigration...

Explanation:

Hope it helpzz!!

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).

because they can and they wanted to.