A system and method of forming differently sized and/or textured construction blocks from a single mold. The system includes a mold having a base and movable side walls that cooperate with the base to form a mold cavity, and one or more inserts that are configured to be positioned in the mold. The mold is arranged and oriented so that its side walls form the top, bottom, front, and rear surfaces of each block. The inserts may be used individually or grouped together into predetermined sets to form different blocks, such as interior and end blocks, as well as cap stones.