Here is the area in 1963 with the road highlighted with green. The insurance company was of course there already but I wonder whether it was going by the name Caroline or was actually renamed to Mutual Drive at that point. Looking at the aerial photos from 1930, the road was there as well so I assume it was indeed there as far back as 1855 as your map shows.
Looks like the hospital had quite a nice garden where the parking garage is as well.
Looks like the hospital had quite a nice garden where the parking garage is as well.