Originally Posted by sambouchah
About how long should this take?
The first one should appear quite quickly, within 10 frames at the most. If you have a meeting zone or meeting hall set and accessible from the surface, the first migrant should quickly start moving towards it. Otherwise, the first migrant will wander randomly until they've become "naturalized" (meaning the grey X stops flashing over them). Additional migrants will appear after the first one has moved.
If you're having difficulty finding your fort, hit F1. This hotkey is set to where your initial wagon was unless you've changed it. You might also try hitting TAB a few times. This will toggle the sidebar and/or map on and off, and since the map is kind of useless toggling it so that the sidebar shows up and the map doesn't will show twice as much of the main playing view.