Here's how I'd like to see it play out:
Think about the settling of the West. Early on, it was small groups of hunters and trappers barely making it through. They'd know a little bit about everything and probably be pretty tough. The only legendary dwarves would be hunters and explorers -- but they'd be wanderers, staying for a little while then leaving. Family's are almost non existent, except for those started at the fort. The only caravans that show up are dwarven ones, unless there is an extremely close settlement of another race.
Once the word gets out the fort has made a lot of money, a gold rush type thing happens where tons of single dwarves looking to get rich head there. Expect mid level trade skills and professional warriors. There might be the occasional family at this stage, but children are still rare. Caravans from all races begin to show up, looking to make money off of the new found wealth.
Next, the fort starts to get high level nobility and is a major part of the economy of the kingdom. Families feel it is safe to travel to the fort, bringing with them very high level trade skills of many different types with the trade off that they bring 'useless' children and spouses who may not have the same high level of skill. Immigrants from other species begin to arrive, bringing with them new art styles and closer relations at the cost of different needs and possible diplomatic snafus.
Finally, the fort becomes the new Mountainhome and permanent diplomatic envoys from other races are set up. The fort's population stabilizes as the maximum limits of the mine become apparent. Caravans begin setting off from the fort to trade and set up new mines with the excess population.