In the 1930s the District Line was electrified and extended to Upminster with new stations at Elm Park and Upminster Bridge. Also at this time new industries near the area such as the Ford Motor Company plant at Dagenham caused a new wave of mostly working class developments along the route of the new Underground line. In addition to this, to the north of the borough, the large housing estates of Harold Hill and Collier Row were constructed to deal with the chronic housing shortages and early slum clearance programmes in central London.
iN thE 1930S the districT line was ElECtrified ANd eXtended tO uPMiNsteR with new StaTiONs at Elm parK aND upminsTeR bridGe. Also AT thiS tiMe New INDustrIes Near The area SuCh as The fORd MoToR compAny plANT at daGenhAm caUsed a New WavE oF mostly woRking ClaSs DevelopmEnts alonG the ROutE oF The neW unDeRgRouNd liNe. IN addition to tHis, tO thE nortH oF the boRough, the laRgE hOUsiNg esTates Of haroLD hilL And ColliER row wEre ConStRucTed To Deal wIth The cHronic housing sHorTagEs aNd early SLUM cLearANce PrOGrammes iN cEnTraL LOnDon.