1/2 cup all purpose flour
2 cups whole wheat flour
1/2 cup molasses
2 cups buttermilk
2 teaspoons baking soda
1 teaspoon salt
optional 1 cup raisins

Lightly coat three 19 ounce cans with vegetable oil. Mix all ingredients together thoroughly and then fill each can just two-thirds full. Let the batter rise for a half hour, then bake in a 350? oven for 40 to 45 minutes, or until a toothpick comes out clean. Cool the "baking tins" until you can handle them easily, then slide a thinbladed knife around the loaves and shake them out.

Note: I remember my mother bought canned brown bread. I couldn't find that product in Louisiana, and no wonder why, its a New England product!
Source: VIOLA B. STEWART'S BOSTON BROWN BREAD