Census years are 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880, 1890 is pretty much lost, 1900, 1910, 1920 and soon to come 1930. For Armstrong County you won't find anything prior to 1800. Before that,some of what is now Armstrong County was included in Westmoreland County (the southern part) and the northern part seems to have been part of Lycoming county in 1798, but Northumberland in 1790. The far western part of Armstrong County was included in Allegheny County after being dome of the Depreciation lands. Any census prior to 1850 will have VERY minimal information. Linda Mockenhaupt