The colony that became Ontario arose almost spontaneously out of the confusion and uncertainty following the American Revolution, as a quickly chosen refuge for some 10,000 Loyalists who had to leave their former homes. After the War of 1812 settlers began to spread throughout the inter-lake peninsula that was to become southern Ontario and by the middle of the nineteenth century expansion had led to a diversifying agriculture and an increasingly open farming landscape that replaced a mature forest ecosystem. The scale of the change from forest to cropland profoundly affected what had been for many decades a rich environment for life forms, from large herbivores down to microscopic creatures. In Making Ontario David Wood shows that the most effective agent of change in the first century of Ontarios development was not the locomotive but settlers attempts to change the forest into agricultural land. Wood traces the various threads that went into creating a successful farming colony while documenting the sacrifice of the forest ecosystem to the demands of progress, progress that prepared the ground for the railway. Making Ontario provides a detailed focus on environmental modification at a time of great changes. It is liberally illustrated with analytical maps based on archival research. J. David Wood is professor of geography and urban studies at Atkinson College, York University.