Put the rhubarb in the crust and cover with 1/2 cup sugar.
Add the other 1/2 cup sugar to the milk and beaten eggs, and pour mixture over rhubarb.
Sprinkle top with cinnamon.
Bake at 350 degrees for 45 minutes; let cool before serving to allow custard to set.
Note from Julie: this was my dad's favorite pie, and my mom got the recipe from his mother.
Note, again: I've been on the 'net for a very, very long time, and this is one of the earliest recipes that I submitted to any search engines. What I can say: it's a tried and true recipe, one we've been using for well over 50 years. It's what my mom will be serving at Christmas this year... what else can I say?