Mix the cracker crumbs, sugar, and butter together. Line a 9-inch pie tin with the cracker mix, pressing firmly to line bottom and sides. Bake for 8 minutes.
This makes enough crust for about 4 pies
Whisk the condensed milk with the lime juice and egg yolks in a stainless steel bowl. Pour into the pre-baked graham cracker shell. Set aside while making the meringue.
Beat the egg whites to a soft peak; add cream of tartar and continue to whip to a stiff peak. Continue whipping and add the sugar, whipping until the meringue forms stiff peaks. Decoratively add meringue on top of the custard.
Bake for 15-30 minutes at 350 degrees. Cook until the meringue has good color. Check with a wooden skewer or cake tester to be sure the custard is done.