The volume, extent, and international importance of the archaeological material from the 18th to the 20th century makes it one of the most important periods, if not the most important period, in the region. Innovations in manufacturing processes and urban living developed in the region had a national and international impact, whilst also connecting North West England with emerging global trading networks and the mass movement of people internationally. Archaeological evidence, whether it be from the perspective of post-medieval archaeology, industrial archaeology, or 20th century archaeology studies, is crucially important in understanding the massive landscape and material culture changes of the era, providing unique types of data and a volume of material that can provide a corrective to the contemporary literature. A feature of the 20th and early 21st century is the rate of loss of documentary, pictorial, and photographic evidence, leaving archaeological approaches as the main means of recovering information about many of the sites and landscapes new to the period.
There is a notable increase in the scale and volume of sites and material culture from the 18th century onwards. The sheer scale and diversity of the archaeological resource, including the built heritage is vast and daunting when it comes to recording and interpretation. How to record and promote research on this material remains a challenge. The rise of professions in the 19th century such as architects, surveyors and engineers resulted in additional documentary evidence, alongside more traditional material from business, municipal and other records. Where this survives it provides cross-disciplinary opportunities to work with architectural, cultural, and social historians. Furthermore, the introduction of new building materials such as glass, steel and cast-iron framework provides opportunities to work with materials science specialists. Likewise, the impact of industrialisation on the flora and fauna of the North West gives opportunities to work with environmental historians to provide a more holistic approach to the rural and urban changes of the 18th to 20th centuries.
Since 2006, the level of archaeological work in this period has remained high with fieldwork undertaken by community, professional, and academic archaeologists. There has been a significant number of excavations of graveyards, with analysis on human remains leading to important work on the health of populations living in the industrial towns and cities of the region. Changes in agricultural practice in the early 21st century and urbanisation have continued to provide opportunities for recording rural farms and communities, whilst a number of landscape surveys have targeted the impact of agricultural intensification and industrial pollution on rural communities across the North West. The development of travel infrastructure for people and goods, transatlantic trade, and population movements are especially key themes for the North West during this period and there has been some progress in recording linear transport monuments and the impact of population movements through the analysis of human remains and material culture studies. Recording and research continues to recognise sub-regional variation in houses, mills, and public buildings, whilst the national study of building types, from petrol stations garages to railway signal boxes have a direct relevance for the region.
Archaeological studies form this period are increasingly theoretically informed and focussed, although such approaches are by no means universally applied. Making sure that an archaeological perspective is at the centre of projects dealing with sites and material from the 18th to 20th centuries is crucial to maintain the credibility of archaeology as discipline in a period blessed, or cursed, with a huge variety and volume of source material.