Residents of Markham — Sub-district C, surnames I (1881 Census)
| # | Surname | Given | Sex | Age | Religion | Origin | Birthplace | Occupation | HH |
| 25 | innis | alexander | M | 22 | Presbyterian | Scottish | Scotland | Labourers nfs | 25 |
| 20 | irwin | abigail | F | 9 | Presbyterian | Irish | Ontario | No Occupation Listed | 9 |
| 19 | irwin | ada | F | 9 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 16 | irwin | ann | F | 32 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 18 | irwin | bertha | F | 11 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 15 | irwin | edwin | M | 25 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 9 |
| 17 | irwin | emery | M | 13 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 4 | irwin | esther | F | 65 | Methodist | English | England | No Occupation Listed | 10 |
| 21 | irwin | ethel | F | 4 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 2 | irwin | george | M | 26 | Methodist | English | England | Farmers, general and nfs | 10 |
| 21 | irwin | joseph | M | 7 | Presbyterian | Irish | Ontario | No Occupation Listed | 9 |
| 19 | irwin | maggie | F | 12 | Presbyterian | Irish | Ontario | No Occupation Listed | 9 |
| 20 | irwin | maretta | F | 6 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 14 | irwin | margaret | F | 48 | Presbyterian | Irish | Ontario | No Occupation Listed | 9 |
| 3 | irwin | margaret | F | 26 | Presbyterian | Scottish | England | No Occupation Listed | 10 |
| 22 | irwin | maud | F | 2 | Primitive Methodist | English | Ontario | No Occupation Listed | 47 |
| 16 | irwin | nellie | F | 20 | Presbyterian | Irish | Ontario | No Occupation Listed | 9 |
| 13 | irwin | samuel | M | 52 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 9 |
| 18 | irwin | sarah | F | 13 | Presbyterian | Irish | Ontario | No Occupation Listed | 9 |
| 17 | irwin | william | M | 16 | Presbyterian | Irish | Ontario | Farmers, general and nfs | 9 |
| 15 | irwin | william | M | 43 | Primitive Methodist | English | England | Farmers, general and nfs | 47 |