This section is not specific to Essex maps, but rather applies to all UK antique maps. Indivual counties' Cartobibliographies have their own page.
There are a few books that list out the County Atlases published from 1579 to a variety of dates; the original one was published by Chubb in 1927, covering 1576 to 1870, so this is now mainly superseded by the Skelton and Hodson books.
Chubb, T. The Printed Maps in the Atlases of Great Britain and Ireland, A Bibliography 1579-1870, Martino Publishing, CT, USA, 2004 (original 1927)
Skelton, RA. County Atlases of the British Isles, 1579-1850, London, 1970 (Actually only up to 1703; Refs SH1 to SH124; superb successor to Chubb.)
Hodson, D. County Atlases of the British Isles published after 1703, Volume I 1704 to 1742, Tewin, 1984. (Refs SH125 to SH193; superb follow on to Skelton.)
Hodson, D. County Atlases of the British Isles published after 1703, Volume II 1743 to 1763, Tewin, 1989. (Refs SH194 to SH232)
Hodson, D. County Atlases of the British Isles published after 1703, Volume III 1764 to 1789, BL, 1997. (Refs SH233 to SH286)
The numbering system used in the Hodson books follows on sequentially from that used by Skelton, so we have a continuous range (SH1 to SH286) covering 1579 to 1789. These books are superb, but cost £35-£50 each these days.
There are other books that list other types of atlases and/or maps.
Bennett, Francis. Road-Books, Road-Maps & Itineraries of Great Britain 1535 to 1850, Menryn, 2007. (Cartobibliography of both road strip maps and of other maps that are specifically designed to show roads.)
Kentish, B. Large Scale County Maps of England and Wales 1705-1832, Parchment Press, Oxford, 1997. (One or two large scale maps per county.)
Nicholson, TR. Wheels on the Road, Road Maps of Britain 1870-1940, Geo Books, Norwich, 1983. (101pp)
Rodger, EM. The Large Scale County Maps of the British Isles 1596-1850, Bodleian Library Oxford, 1972. (Individually published Maps, rather than in Atlases.)
Shirley, RW. Printed Maps of the British Isles, 1650 - 1750, Map Collector Publications Ltd & The British Library, London, 1988. (Alphabetic listing of cartographers, 167pp.)
Smith, D. Victorian Maps of the British Isles, Batsford Books, London, 1985. (176pp)
Tooley, RV. Maps and Map-Makers, Bonanza Books, New York, 4th edition, 1970. (127pp + plates)
Andrews, JH. Maps in those Days, Four Courts Press, Dublin, 2009 (549pp). Excellent explanations of how antique maps were made.
Barber, P and C Board. Tales from the Map Room, BBC, London, 1993. History of the usage of maps.
Delano-Smith, Catherine, & JP Kain. English Maps: A History, University of Toronto Press, 1999 (320pp). Excellent overview of of maps in England from earliest examples to modern times.
Worms, L & A Baynton-Williams. British Map Engravers, Rare Book Society, London, 2011 (744pp). Excellent biographies and bibliographies of hundreds of engravers and associated map people.