So, you've worked your way backward in time tracing a family line through all the census years, only to run into a very dense "brick wall" prior to 1790. Your research has taken you to what historians designate the "Colonial" period in the United States. This time period runs roughly from 1600 to 1775, though there are reasonable arguments that the time period should go up to 1782 and the ratification of the U.S. constitution. No matter. The question is, where do you go from here to find your ancestor? One answer is tax records.
In the Colonial era, tax records were based on "real property" which includes land, but in many cases also included tax on cattle, hogs and sheep. Taxes on land were also called tithables; but the term usually applied to people who were to pay taxes, or have taxes paid on their behalf. Depending on which colony your ancestor lived in, the money collected through these tithes might go to support a church or to the support of governing the colony. Another type of tax was called a quit rent, and there was a category called a poll tax.
When a male reached a certain age, he was considered tithable. Tithables were required to pay taxes whether or not they owned land or other personal property. Depending on the colony, a man became tithable at age 16 to 21. These annual taxes were due until they reached age 50 to 60, again based on the colony in question. Tracking your ancestor through these tithable lists can be tricky. The name of the male head of a household was placed on the list. His male offspring who had reached tithable age, but were not yet the head of a household, were counted as a tally mark on the record or simply one of a number. However, by researching the requirements for a particular colony's tithables list, and reviewing those lists for year after year, will often yield positive results. A marriage record, combined with the sudden appearance of a name on the tithables can help you determine if the "John Brown" on the tithables list is indeed the John Brown for whom you have been searching.
A quit rent was a land tax based on the English feudal system. Instead of providing a land owner with a yearly portion of your crops and stock, a small fee was paid. Upon payment, the obligation was "quit." If your ancestors lived in New England during the Colonial period, you won't find their names on any quit rent records. New Englanders dropped this category of tax almost as soon as they arrived in the New World. But from New York to the south, quit-rent fees were paid to the Crown or property owners up until the Revolutionary War, when they were abolished.
Poll taxes were general revenue taxes and were "due" on every free man above the age of 21 and on every slave or servant above the age of 16. Again, a parent might pay the tax for a son. Persons who had slaves paid the tax for each slave they owned; the same for servants. In later years the poll tax is associated with voting rights and only property (land) owners were allowed to vote.
All of the above types of taxes have exceptions based on the colony in question. Researching the history of a particular colony is absolutely necessary in genealogical research. For example:
In Colonial Virginia, taxes on tithables went in support of the government; however, the categories considered tithables included not only the free white males, but slaves and Native American servants, both male and female, age 16 and older. No complete list of tithables is available for the state; however the Library of Virginia does have full or partial lists for roughly 36 counties. Also note that in Virginia, the age- 16 rule for slaves only included those in the "work force." As with the rest of life, genealogical research contains exceptions to every rule.
You will need to research each colony separately to see what resources are available. In general, you will find very few for the Southern colonies because most of the records were later destroyed during the War Between the States. However, there are a few exceptions, (The state of South Carolina has a tax list from 1733.), so leave no stone unturned. As always, utilize your local genealogical library and the nearest Family History Center operated by the Church of Latter Day Saints. Contact genealogical societies in the state you are researching to see if they have microfilm copies or researchers available. Remember that there was no federal government in the Colonial years, so these lists will not be found at the National Archives and Records Administration offices.
For online research I always urge beginners, and remind the experienced, to utilize Cyndi's List for both free and fee-required resources. With more than 100,000 links in multiple categories, it should keep you busy for quite a while.