Disappointment

Cape Disappointment in Washington is named after a fur trader's minor disappointment in 1788: He was unable to find a way up the Columbia River. Still, it was a difficult problem for him, and far be it from people in the modern era to discount it simply because it's not a modern sort of disappointment.

The lighthouse there was completed in 1856, after a number of difficulties including the loss of a ship that was carrying the building supplies - on the very bar that the lighthouse was intended to help. It was one of several lighthouses approved by Congress for the West Coast,  most of them in the recently added state of California. When the Civil War started five years later, additional fortifications and guns were placed there

This would place it in the Third Turning, not normally a major period for government investment. Then again, options for the Transcontinental Railroad were under investigation at this same time. The total cost of these lighthouses was relatively minor. Perhaps it all goes together: The entrepreneurs pushing for the railroad needed safe passage for ships in order to deliver materials needed. Particularly those on the west coast, who would eventually be required to acquire their resources (e.g. steel for tracks) from within the United States. This necessitated purchases in the Eastern United States followed by water transport to the western construction sites. Getting some government assistance for projects like this is not at all unusual.