Final answer:
The Erie Canal, opened in 1825, connected the Great Lakes to the East Coast, fueling New York City's economic rise by offering efficient transportation for goods and aiding western expansion.
Step-by-step explanation:
The construction that connected the Great Lakes to the East Coast and was instrumental in the economic ascent of New York City was the Erie Canal. Opening in 1825, the Erie Canal transformed transportation and commerce in the United States by offering a direct water route from Buffalo, on Lake Erie, to Albany on the Hudson River, which flows down to New York City. This canal system not only provided a more efficient way to transport goods, but also facilitated western expansion and helped to establish New York as a dominant economic center. The success of the Erie Canal catalyzed what is known as 'Canal Mania,' prompting the development of further canal projects across the nation.