In compliance with the United States' constitutional requirement to count the country's population on a ten year basis, federal census enumerators visited every home and establishment across the nation. Beginning in 1790, they were instructed to records information, such as the age, sex, race and occupation of each inhabitant. Individual states took their own census on a five year schedule. Since small towns, such as Barry, Baylis and New Philadelphia, Illinois, were reported collectively under the heading of Hadley Township in the mid- to late 19th century, determining exactly who lived in New Philadelphia during that time and their personal characteristics is challenging. The quality of microfilms preserving the census records themselves as well as the legibility of penmanship and interpretation of reporting instructions by the enumerators posed additional challenges.

A small cluster of individuals recognized as entrepreneurs and residents of 1850 New Philadelphia facilitated isolating the townsfolk from the rest of Hadley Township. Identifying New Philadelphia residents from the rest of the township on subsequent census reports, however, was not as straight forward; maps, land deed records and historical reports helped define the populace. Oral histories recently collected from town and area descendants are further identifying New Philadelphia's townsfolk.

In 1850 and 1860, census enumerators were instructed to leave the field recording "color" blank for white people and to insert a "B" for black individuals; an "M" in that column represented the mulatto designation. In 1870 and 1880 those instructions were revised; enumerators were cautioned not to leave the space blank. Some enumerators chose to write "ditto" to indicate a repetition of information from the record above. Unfortunately, other enumerators chose to insert a quotation mark (") to indicate a repetition from the record above. Because of the poor quality and damage to either the original document or the microfilm on which it is stored, the marks are sometimes questionable and confusing.

Census records show that settlement in Pike County, Illinois boomed in the years following New Philadelphia's founding in 1836. The town straddled major county crossroads; construction of the Illinois-Michigan Canal promising to further facilitate transportation of goods and individuals also attracted new settlers. By 1850, 58 residents lived in 11 households. New Philadelphia boasted a Baptist preacher, a cabinet maker, a laborer, a merchant, two shoemakers, a wheelwright and four farmers. While 20 town residents, 35% of the population, were recorded as "mulatto," the majority of the residents, 36 individuals, or 62%, of all the townsfolk were listed as white. Two individuals, or 3%, were recorded as black. The state of Illinois reported only 0.6% black residents on the 1850 federal census.

Thirty-seven percent, or 22 residents, were born in the Great Lakes region of the country. Twenty-two percent of the townsfolk, 13 individuals, originated from the state of Illinois. The next highest representation came from the New England and North East regions, each with 11, or 19% of New Philadelphia's residents.

In addition to McWorter, the names Burdick, Clark and Hadsell first appeared on the census in 1850 and they continued to be associated with the town for years to come.

Frank McWorter died a year before the 1855 state census was taken, but the town he founded continued to grow. Eighty-one people, an increase of 40% from the federal census taken just five years earlier, now lived in the town. The 18 black residents accounted for only 22% of the populace; white residents were in the majority with 63 individuals, 78% of the townsfolk. Occupations were not recorded, but the town's livestock was valued at $3,230; an average of $215 for each of the town's 15 households.

By 1860, 114 people lived in New Philadelphia. The 1860 federal census reported that a blacksmith, a carpenter, a physician, a schoolteacher and additional farmers and farm workers had joined New Philadelphia's workforce. Ninety-three New Philadelphians, 82% of the town's 114 residents, were white; 21 individuals, 18% of the populace, were recorded as black and mulatto. New Philadelphia was still well ahead of the state of Illinois in its representation of black residents. The entire state reported only 0.4%, or 7,628 black individuals, among a populace numbering 1,711,951 citizens. Restrictive and prejudicial Black Codes most likely contributed to the low number of black and mulatto individuals residing in the state.

The town continued to attract settlers from other Illinois communities; 50 individuals, 44% of the population, claimed Illinois as their place of origin. Twenty-four people, 21% of the population, originated from the North East region of the country, including the states Maryland, New Jersey, New York and Pennsylvania. The large number of settlers from the North East may have come to escape the economic chaos experienced in the East at the time; in pursuit of affordable land available on the frontier; and in answer to advertisements that appeared in east coast newspapers (McCartney 1988). Economic opportunity may also have lured settlers to the region. Two of the town's residents, about 2% of the population, were born in Ireland.

New Philadelphia's population peaked by the time of the 1865 state census with 160 individuals living in 29 households. Those 160 individuals represent an increase of 40% from the 114 residents reported in 1860 and reflect an increase of 175% from the 58 individuals reported on the 1850 census taken only 15 years earlier.

The total value of livestock owned by the town's residents now totaled $8,700, and increase of $5,470, or 169% more than 10 years earlier in 1855. However, only 9 of the town's 29 households, or 31%, reported owning livestock. In 1855, 14 of the town's 15 households, or 93%, reported owning livestock. Seven, or 24% of the town's households produced 354 pounds of wool. Wool production was not reported on the 1855 state census. Geographic origin and occupational distribution were not reported on the 1865 state census.

New Philadelphia remained a bi-racial town, but the majority, 112 individuals, or 70% of the population, was white; 48 individuals, or 30%, were recorded as black. Although the majority of residents were white, the number of black and mulatto individuals had more than doubled in just 5 years, from 21 to 48 individuals. The large influx of black and mulatto residents may be attributed to the migration of formerly enslaved people moving from the South following manumission.

The Burdick, Hadsell, Clark, Cartwright (Kirtwright), Vond and McWorter families still figured prominently in the history of the town as residents and landowners; the Bower, Kellum, Hadsell and Baker families were among New Philadelphia townsfolk in 1865.

When the Hannibal-Naples Railroad bypassed New Philadelphia in favor of nearby towns Hadley and Barry in 1869, New Philadelphia was doomed. Town residents moved away in search of jobs and economic opportunities elsewhere. The 1870 federal census reported 123 individuals living in the town, a decrease of 23% from 1865's peak report of 160 individuals. Seventy-five percent of the population, 92 individuals, were white. Twenty-nine individuals, 23% of the population, were listed as mulatto; only 2 residents, less than 2% of the townsfolk, were recorded as black on the 1870 census. The Burdick, Clark and Hadsell families continued too hold a presence in the community.

While New Philadelphia's population was declining, the state of Illinois experienced continued population growth, but not as dramatic as the increase from 1850 to 1860. The federal census of 1870 reported 2,539,891 people residing in the state, an increase of 48.4% over 1860's count. The majority of the population, 1,704,291, or 98.9% of the state population, was white, but the 28,762 black residents represented 1.1% of the state's population, an increase of 0.7% from the census of 1860. Those figures reflect an increase of 21,134 people, or 277%, from the 1860 census that recorded 7,628 black residents. Although restricted by the state's stringent Black Codes, people freed from slavery and eager for economic opportunities and self-determination made their way to Illinois.

The town's occupation distribution also changed in the years between 1860 and 1870. In addition to one carpenter, two blacksmiths now lived in the town and a coal miner joined the community. There were 3 schoolteachers living in New Philadelphia in 1870 along with a physician, a minister and 3 laborers. Farming occupied 21 of the 34 townspeople, or 61% of the population, who were gainfully employed outside the home. A seamstress, shop worker, 3 school teachers and a speculator rounded out the town's workforce. In 1870, as past years of New Philadelphia's history, most of the town's populace, 79 individuals, or 64% of the population, originated from the Great Lakes region of the country. Illinois again held the largest representation with 69 individuals, or 56% of the populace. The South Central region of the United States, including Kentucky, Tennessee and Missouri, was represented by 13 individuals, 10% of the population. The relatively large number of settlers from that region is most likely attributable to the migration of freed people moving away from the South.

The majority of New Philadelphia's population, 92 people, or 75% of the population, were white. The 2 black and 29 mulatto individuals represented the minority, or 25% of the total number of townsfolk.

By 1880 the population of New Philadelphia had plummeted to 84 individuals, a reduction of 31% from the 122 individuals reported in 1870 and a 48% decline from the town's population peak of 160 residents in 1865. The number of 17 households in 1880 represents a reduction of 41% from the town's peak of 29 households in 1865.

While New Philadelphia's population declined, the state of Illinois' population continued to grow. In 1880, the state's population included 3,077,871 people, an increase of 21.2% over 1870's number of 2,539,891.

Black individuals living in Illinois now numbered 46,368 representing 1.5% of the state's total population, and reflected an increase of 61.2% over the 28,762 included on the 1870 federal census. In New Philadelphia, white residents, 70 individuals, or 83% of the population, continued to maintain the majority racial representation of the town. New Philadelphia's 14 black and mulatto individuals represented the minority, 17% of the populace.

Most of New Philadelphia's townsfolk, 20 individuals, or 24% of the total population continued to be occupied in farming. That number represents 64%, or 31 individuals gainfully employed outside the home. A school teacher, a store keeper, a house servant and a blacksmith also lived in the town. Thirty-two individuals, 38% of the populace, were recorded as "at home." For children "too young to be involved in production," census enumerators were instructed to mark the occupation column of the census form "at home." The town's 28 children 14 years of age and under are reflected in the "at home" group. However, other individuals listed as "at home" ranged from infants to 34 years of age, another indication that census enumerators sometimes took liberty with interpretation of their instructions.

The majority of the town's residents, 67 individuals, or 80% of the population, originated from the Great Lakes region of the United States. Fifty-two individuals, or 62% of the population, were Illinois natives, including 29 adults and 23 children under 14 years of age.