Tundra and cold temperatures kept the Chinese
from expanding in which direction?

Northern direction.

Explanation:

The Chinese have developed one of the earliest civilizations in the world and it has managed to persist for millenniums. Unlike many other civilizations though it is easily noticeable that the Chinese remained in roughly the same area for more than 2,000 years, which might seem weird considered the power of the country and that it was more than capable to expand throughout history.

There were several reasons as to why China did not expand further and one of them is the climate. China never expanded northwards an it didn't really seemed to be interested in it. Not just that they would have had to have open wars on open ground with the Mongol and Turkic tribes, but what they would have got int their territory would have been taiga and tundra. Both of these places are not of much use for a civilization, with the main problems being the extremely low temperatures and lack of resources.

the tariff was created to protect industry in the northern part of the united states. industries in the north were being driven out of business by imported goods that were priced at a low rate. the goal was to protect these industries   by taxing the goods.

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.