By pre-income-tax Americans, I assume you mean the United States before the creation of the Internal Revenue Service and the income tax during the Civil War? The income tax was declared unconstitutional after the war and re-instituted during the First World War - but I'm guessing you're talking about the antebellum period here.

At the federal level, the main form of taxation was the tariff, which represented about 80-95% of government revenues during the period from the 1790-1860. The tariff was a duty on foreign products, typically manufactured goods, which was collected by customs agents in port towns. There was a good deal of controversy over tariff rates - Northerners wanted them high enough to protect American manufacturers against foreign competition (a protective tariff), while Southerners and many Westerners wanted them low enough that they wouldn't raise the price of goods (a revenue-raising tariff). But one way or the other, the tariff remained the most important source of federal revenues.

The federal government also imposed excise tariffs from the 1790s through 1815 on a number of goods such as whiskey, rum, tobacco, and refined sugar. When someone sold these goods at retail, they were expected to pay a small percentage to the federal government. Excise taxes were abolished in 1834, though, and did not return until the Civil War.

At the local and state level, there was a lot of variation in tax assessments, but the system became more standardized by the 1830s. The main form of taxation was the property tax, which was assessed on all forms of property (land, capital, slaves, etc.). The rate of taxation was set by the state legislature (at say, 1/2 or 1/4 of 1% of total assessed value). Assessors at the county level would then make estimates of the value of taxpayers' estates (typically ad valorem, meaning the market value of property), which they would collect on an annual basis. The property tax could also be supplemented by a poll tax, i.e., a tax on heads of households, regardless of property values.

In general, levels of taxation in the United States before the Civil War were very low. (This was true even during the colonial period - at the time of the Revolution, British North Americans were one of the most lightly taxed peoples in the Western world.) According to one estimate, a typical laborer in the 1790s could have paid his federal tax burden through four days of work during the year.