1 9 th ▁century , ▁military ▁engine ers ▁in ▁the ▁Army ▁Corps ▁built ▁brick ▁and ▁m ason ry ▁se aco ast ▁fort ifications . ▁After ▁ 1 8 2 4 , ▁two ▁Army ▁Corps ▁of ▁Engine ers ▁existed ▁in ▁the ▁United ▁States . ▁One ▁of ▁them ▁was ▁responsible ▁for ▁building ▁fort ifications ▁while ▁the ▁other ▁was ▁responsible ▁for ▁impro ving ▁the ▁country ’ s ▁har b ors ▁and ▁rivers . ▁The ▁two ▁corps ▁occasionally ▁over la pped , ▁especially ▁during ▁times ▁of ▁war . ▁The ▁two ▁corps ▁un ited ▁as ▁one ▁and ▁expanded ▁in ▁ 1 8 6 3 ▁in ▁the ▁midst ▁of ▁the ▁American ▁Civil ▁War . ▁With ▁the ▁adv ancement ▁of ▁war fare ▁technology , ▁the ▁Army ▁Corps ▁of ▁Engine ers ▁had ▁to ▁expand ▁their ▁knowledge ▁of ▁building ▁brid ges ▁and ▁facilities ▁capable ▁of ▁handling ▁heav ier ▁art illery . ▁ ▁Tw enti eth ▁and ▁twenty - first ▁century ▁During ▁World ▁War ▁I ▁and ▁World ▁War ▁II , ▁military ▁engine ers ▁built ▁roads , ▁brid ges , ▁rail ro ads , ▁ports , ▁fort ifications , ▁tren ches , ▁and ▁dep ots ▁in ▁battle field ▁situations . ▁These ▁engine ers ▁emer ged ▁as ▁important ▁factors ▁in ▁war fare ▁both ▁on ▁the ▁front ▁lines ▁and ▁behind ▁those ▁lines . ▁Speed ▁became ▁a ▁significant ▁factor ▁in ▁these ▁times ▁of ▁war ▁because ▁of ▁the ▁adv anc ements ▁in ▁equipment ▁and ▁art illery ▁on ▁both ▁al ly ▁and ▁enemy ▁lines . ▁The ▁task ▁of ▁building ▁infrastr ucture ▁in ▁a ▁tim ely ▁manner ▁became ▁more ▁important