. ▁Carl ▁Klein , ▁the ▁leader ▁of ▁a ▁group ▁of ▁early ▁German ▁sett lers ▁who ▁led ▁the ▁project ▁to ▁establish ▁the ▁community ▁though ▁Henry ▁G ann ett ▁stated ▁that ▁the ▁name ▁derived ▁from ▁the ▁city ▁of ▁Kar lov ac ▁in ▁Cro atia , ▁which ▁was ▁known ▁as ▁" Car l stadt " ▁in ▁German . ▁The ▁Bor ough ▁of ▁Carl stadt ▁was ▁incorpor ated ▁on ▁June ▁ 2 7 , ▁ 1 8 9 4 , ▁formally ▁set ▁off ▁from ▁Ber gen ▁Township . ▁The ▁bor ough ▁was ▁formed ▁during ▁the ▁" B or ough itis " ▁phenomen on ▁then ▁swe eping ▁through ▁Ber gen ▁County , ▁in ▁which ▁ 2 6 ▁bor ough s ▁were ▁formed ▁in ▁the ▁county ▁in ▁ 1 8 9 4 ▁alone . ▁ ▁Geography ▁According ▁to ▁the ▁United ▁States ▁Census ▁Bureau , ▁the ▁bor ough ▁had ▁a ▁total ▁area ▁of ▁ 4 . 2 4 3 ▁square ▁miles ▁( 1 0 . 9 8 9   km 2 ), ▁including ▁ 3 . 9 9 9 ▁square ▁miles ▁( 1 0 . 3 5 8   km 2 ) ▁of ▁land ▁and ▁ 0 . 2 4 4 ▁square ▁miles ▁( 0 . 6 3 2   km 2 ) ▁of ▁water ▁( 5 . 7 5 %). ▁ ▁Carl stadt ▁is ▁border ed ▁on ▁the ▁south ▁by ▁East ▁R uther ford ▁in ▁Ber gen ▁County , ▁Sec au cus ▁and ▁North ▁Ber gen ▁in ▁Hudson ▁County , ▁on ▁the ▁north ▁by ▁Wood - R idge ▁and