I don't know the history of the boil but I suspect it has to do with the availability of inexpensive ingredients and the need to feed large groups of people. Here in the southeast US there are many who have made their living off the waters as is in other parts of the world, our claim to fame is shrimp and all who eat them from here of course say they are the tastiest they have ever had the opportunity to enjoy!
The key to making this dish is cooking time. Too little and the potatoes will not be cooked, too much and your shrimp will be rubbery. I am going to tell you how much I used to feed about 20 folks with left overs and you can head from there. We used a turkey fryer to cook ours but I suppose if you have a very very large stock pot it could be made on the stove.
Low Country Boil
8 lbs shrimp (heads off, shells still on)
15 ears of corn (shucked and broken in half)
6 lbs small red potatoes
6 lbs kielbasa cut in 1 inch pieces (we used beef but pork is fine)
1/2 container Old Bay seasoning
1 lemon cut in half
Place 8 quarts of water into pot, add the Old Bay and lemon. Bring water to a boil and put in the potatoes cooking covered until fork tender. Add the corn and kielbasa re-cover and cook for about 15 minutes or until corn is tender. Add the shrimp cover and cook until shrimp are pink (you want to watch it at this point).
So the cost for this feast...
Shrimp 8lbs with the heads on 3.00 a pound = 24.00
Beef Kielbasa 6 lbs 3.59 a pound 25.00
Corn 15 ears (10 for 3.00) 4.50
Potatoes (3lbs 3.49 each) 7.00
Old Bay (4.00 a container) 2.00
You can add onions, carrots or even better fresh crab to this recipe and really round it out (the onions were on the menu here but I forgot until I opened the fridge and found them all peeled and ready to go). No one seemed to miss them though!