> This was one of the few railways to survive the great railway crash

The government well made its money back before the great railway crash.

Let's say the Internet suffers a crash in a few decades. Few would argue that any previous investment into the Internet was not worth it.

you're cherry picking an example that succeeded. Let's say DARPA's investment in ESP doesn't turn out in a few decades. Few would argue that any previous investment into ESP was not worth it. (disclaimer: I'm being paid on a stupid darpa grant now)

Non-governmental investment - except for the 3 million acres in Federal land grants.