How to make a rectangular granny square afghan

Starting at center, ch 6. Join with sl st to form ring.

Rnd 1: Ch 3, 2 dc in ring, ch 1, 3 sc in ring, ch 1, 3 dc in ring, ch 1, 3 sc in ring, ch 1; join with sl sto to top of ch-3, sl st to first ch-1 sp.
Rnd 2: Ch 4, work dc, hdc and sc in same sp (first corner made), ch 1, in next sp work sc, hdc, dc, ch 1 and dc (second corner), ch 1, in next sp work dc, ch 1, dc, hdc and sc (third corner), ch 1, in next sp work a second corner, ch 1; join with sl st to 3rd ch of ch-4.
Rnd 3: Work first corner as for last rnd, ch 1, 3 sc in next ch-1 sp, ch 1, work second corner in next ch-1 corner sp, ch 1, 2 dc in next sp, ch 1, work third corner in next corner sp, ch 1, 3 sc in next sp, ch 1, work a second corner in next corner sp, ch 1, 2 dc in next sp, ch 1, join.
Rnd 4: Work first corner as for last rnd, (ch 1, 3 sc in next ch-1 sp) twice; ch 1, work second corner in next ch-1 corner sp, (ch 1, dc in next sp) twice; ch 1, work third corner in next corner sp, (ch 1, 3 sc in next sp) twice; ch 1, work a second corner in next corner sp, (ch 1, 2 dc in next sp) twice; ch 1: join.
Rnd 5 Sl st in first ch-1 sp made on last rnd, ch 4, work 3 dc in next ch-1 sp *. epeat from * to * to next ch-1 corner sp, ch 1, work 3 dc, ch 1 and 1 dc in next sp **. Repeat from ** to ** to next coenre sp, ch 1, work dc, ch 1 and 3 dc in corner sp. Repeat from * to * to next corner sp, ch 1, work a second corner in corner sp, ch 1. Repeat from ** to ** to end, ch 1; join.

Repeat last rnd for desire size.

By the way, this pattern came from a 1973 issue of Woman's Day Magazine's special book on granny squares.
Thanks Kathy...