[1] Concept work was led by proponents at Aerospace Corporation, TRW, and Aerojet General, beginning in the late 1950s.
[1][3] The Sea Dragon was an extremely large BDB/MCD 2-stage launch vehicle defined by Robert Truax and others at Aerojet.
[5][6] TRW also defined a low-cost shuttle-surrogate booster to launch 29 metric tons into a 28-degree orbit at a cost of about $59 million.
Some of the early design concepts were referred to as big dumb boosters, not necessarily in a favorable manner.
As low-tech rocket hardware gets heavier (such as the mass of tanks relative to propellants and the mass of engines relative to thrust), the cost of that hardware (dollars per kg of material) must become vastly cheaper, which explains why a big dumb booster would likely be impractical.