The correct answer to this open question is the following.
Although there are no options attached we can say the following.
I think the federal government was better suited than state governments to manage westward expansion because as the federal government it was, it had more resources, power, strategy, and definition on how to do that settlement expansion into the newly acquired territories after the Louisiana Purchase of 1803.
The evidence to support my reasoning is that it was precisely Thomas Jefferson, the President of the United States, the one who ordered the Lewis and Clark Expedition in order to explore the western territories. After the expedition was over, Merriweather Lewis went to Washington to debrief the President with his final results.
That is when Jefferson authorized the westward expansion to settle the new lands and make them work t make a profit that benefited the American families and the government through taxes.