var map = L.map('map').setView([30.35792, -87.17677], 14);

L.tileLayer('http://localhost:8080/cgi-bin/mapserv.exe?map=C:/OSGeo4W/apps/gbp/gbp.map&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&LAYERS=parcels3857&STYLES=&SRS=EPSG:3857&BBOX=-31856626.987,11633877.801,-31821383.931,11657185.093&WIDTH=400&HEIGHT=300&FORMAT=image/png', {
    maxZoom: 18,
    layers: 'parcels',
    attribution: 'GBP Parcels'
}).addTo(map);

LAYER
    NAME "parcels3857"
    CONNECTIONTYPE POSTGIS
    CONNECTION "host=127.0.0.1 port=5432 dbname=gbp user=abc password=xyz"
    DATA "geom FROM parcels"

    PROJECTION
        "init=epsg:3857"
    END
    METADATA
        "wms_title" "parcels3857"
    END
    STATUS       on

    STATUS DEFAULT
    TYPE POLYGON
    CLASS
      NAME "parcels3857"
      STYLE
        COLOR 227 227 127
      END
    END
  END