Methods of treating a carbon foam precursor to facilitate subsequent foaming of the material at low pressures, which may be on the order of about 0.5 to 1.5 atmospheres, are disclosed. In one embodiment, the carbon foam precursor is subjected to partial devolatilization under controlled conditions with subsequent foaming being effected at low pressure. The carbon foam precursor may be one of various forms of coal including raw coal, coal extract mesophase pitch, synthetic mesophase pitch or petroleum based pitch. The performing treatment of the carbon foam precursor may remove a portion of the internal blowing agent and may alter the fluidity of the carbon foam precursor matrix. In another embodiment, the precursor after being converted into a powder is subjected to oxidation prior to foaming. In another embodiment of the invention a high density carbonaceous material is produced by oxidizing a carbonaceous feedstock to remove from the feedstock volatile gases followed by solvent treatment to remove hydrocarbons thereby providing a carbonaceous feedstock which when coked will produce a material of higher density.