As the ice melted after the last ice age humans started to move into this area following the large animals that they hunted for food, skins and tools. Evidence of that occupation has been found along the Humber River banks and on the hills surrounding the old village. One site was periodically occupied for a span of 8000 years starting about 10,000 years ago. More recent material was left or lost by First Nations peoples who lived here from the ice age until the last tiny family unit appeared in 1871. To the north there was a village that would be occupied briefly, perhaps for a decade every fifty years. This started about 2000 years ago and continued until about the year 1500. Generally over that period the inhabitants were nomadic and believed that they were part of nature and belonged to the land, not the other way around. It is not known if the early European explorers traveled along the valley here, but they may have done so as the river now called the Humber was known to them in the 17th Century.

Peel County (now Region) was not one of the first areas surveyed as settlement started after 1794. Initially it was regarded as an area through which natives could move freely between Lakes Simcoe, Huron and Ontario. In fact when the first Treaty for the southern part of Peel was signed in 1805 a mile wide corridor was left out of the agreement, along the valley of the Credit River, to facilitate continued movement of Natives. The border between the regions now know as Peel and York was originally called the Indian Line (the line between Settlers and Native lands). The second Treaty, which included what is now Bolton was signed in October 1818 by William Claus, representing the British Crown and four male native leaders, representing different 'clans' of the Mississaugas. They were reportedly called Pagilaniguatobe, Cabibonike, Kawahitaguibe,and Weggishgowin. Although this group had been in this area a relatively short time the new arrivals regarded them as 'residents'. Not understanding the concept of land ownership it is fairly clear that the natives were agreeing to 'use' of the land rather than a sale and the mile wide path along the Credit also disappeared. In any case the annual remuneration was only paid for two years.

When survey started in this area the surveyors were paid in land not money. Not surprisingly they knew where the best lots were (those with an additional use to that of agriculture) and the Chief Surveyor, James Chewett (also son of the Surveyor General of Upper Canada) received several potential Mill lots including Lot 9, Concession 7, in Albion Township (200 acres). He quickly sold the land, including the potential mill sites, to bachelor George Bolton who had come to Upper Canada to join relations from Norfolk in England. Although we are uncertain if James Bolton was his brother or perhaps uncle, James (a family man who had a farm a little further north) had experience building mills and built the first Grist (flour) Mill for George. Associated businesses, a cooperage, blacksmith and homes for employees quickly grew up around the Mill and small dam, which were located (not surprisingly) on the bend on Mill Street on the south bank of the river and the east side of Queen Street.

Bolton's Mills became a busy place with wagons lining the street awaiting their turn. The Boltons were educated and advocates of Government Reform. They supported William Lyon Mackenzie and repeatedly helped elect him as their representative. Protesting his ejection from Parliament on what they considered the trumped up charges of the Family Compact, James Bolton prepared wordy petitions which were signed by voters (males) in the community after noisy meetings in the Mill. After the abortive attempt at Rebellion in December 1837, James Bolton although only a Reformer, not a rebel, felt that departure for the United States, like his leader was appropriate. One of his sons went with him. James did not return as he died soon afterwards. Although George was the founder of Bolton it was James' children that subsequently claimed that distinction, purchasing the Mill and other land from George in 1834 and becoming the prominent members of the community. At that time under the jurisdiction of the Township of Albion the village grew quickly, became the central mail depot for the whole area and the highest concentration of population, even though in those days far more people lived on the farms than in the communities. Although 1000 voters (only males) was the bench mark number for application for incorporation to local government, Bolton gained that status in 1872 from the County Council for Peel with 750 voters.

The first Reeve was Notary Public and Land Surveyor, Lambert Bolton grandson of James. His home still stands on the southeast corner of Albert and James Street. The Village had had a railway for a short while at this point and this fact had a considerable impact on the business affairs of the community. For a while it brought great benefits but after the First World War and the arrival of the Depression the railways also carried people away, primarily to the west. After Bolton had its own Council, it started to expand it's borders slightly, every so often, sometimes with opposition from the surrounding Township of Albion, until January 1974 when the Provincial government of Bill Davis, who had also been the local member, introduced sweeping changes to local governments. A slightly expanded Bolton became Ward Five of the new Town of Caledon, in the new Region of Peel.