Robert Patterson died in 1775 in York County, SC. His last will and testament still exists today at the SC Archives. It was penned in 1775 not long after one of his adult sons, James Patterson, passed away. We know that Robert died during the calendar year of 1775, but his birth year is a bit more elusive. He first bought land in Sussex Co., DE in 1732. Since he was described in the 1732 deed as a "yeoman", we know that he was at least 21 years of age, so at the latest, his birth year was 1711. However, it is possible he was born as early as 1705.
Given the sheer number of men named Robert Patterson in colonial America, it has always been difficult to distinguish this Robert from the others. Location is usually the key to separating the Roberts. For example, when Robert lived in VA, his land was described as on or near Linville Creek. The other Robert Pattersons lived further south, so that is one key to keeping them apart in research endeavors. But not all records are land related. Others are court records of one kind or another, and so no landmarks are given in the records.
The signature can be a help in some cases. But that's not conclusive always, since many of the records we see are transcripts in the court books or deed books. Where originals are still available, always make reference to them. Furthermore, many times the person in question did not read or write. In which case, someone else would write their name leaving a space between the names, and then they would add the word "his" or "her" above the name, and then "mark" below the name. At which time, the person in question would make a mark on the document in lieu of their signature.
The Robert Patterson who died near Clarks Fork of Bullocks Creek in York Co., SC in 1775 always made his mark with an "R". To date, we have discovered four such documents that contain his name and the "R" mark. Those documents were created in 1738, 1754, 1770, and 1775. Keep in mind that the York Co., SC land on which the Pattersons lived, was claimed by various counties and even states between the 1750's and 1770's. At first it was Craven Co., SC, then Anson Co., NC, then Mecklenberg (NC), Tryon (NC), and finally York (SC), which it still is today.
Of the four records we've found to date with the "R" mark, the first three are only transcribed versions in the official records (transcribed by the clerks of court). The fourth, however, from the Last Will in 1775, is the original document and therefore his actual mark. The following records are the transcriptions or extracts of each document, their location details, and images of the documents themselves.
Note regarding the 1754 document. That document makes reference to Robert Patterson and two other men who were the appraisers of a deceased man's estate. The second man in that list was named Joseph Bryan. Later in the 1750's, the Bryans, Linvilles, and Boones - who were all intermarried - moved together to the Yadkin River Valley of NC. That is where I personally live today. This same Joseph Bryan was the father-in-law of the famous Daniel Boone.