Hmm, there were several triggering events that promoted westward expansion of the United States. Victory in war over Mexico (1848) gave the US new lands in the west. A treaty with Britain (also in 1848) gave the US sole possession of some formerly disputed Oregon territory lands also. Plus, in 1848, gold was discovered in California (land newly in US possession after that Mexican war treaty), so that prodded westward expansion too. Perhaps those are the initial "turning points" you're looking for. The completion of the Transcontinental Railroad in 1869 sure helped the process as it was underway, as well.
With the ability to forge iron tools, farming tools were more effective and provided a greater production and effectiveness. More food produced means that more people are able to be fed and consequently establish and work in the land. With a higher population and food cap, West Africa settlements were able to grow.
Answer:
This passage doesn't answer this question: what is the actual step/law enacted that will stop slavery?
Explanation:
Researching the rest of the Emancipation Proclamation will answer this question and show why this document is important in history.
The answer to your question is c
The short answer is: "to a great extent". The entire plan of the Federalists was to create a strong central government instead of having many autonomous states. Of course this occasionally went against national unity in the sense that some people were opposed to this plan, but in general they favored unity.