Colonies Thirteen
Nowadays, you can tell that something belongs (or belonged) to the army by the fact that it has “US” or “USA” marked on it. In June of 1776, there was no United States yet, so how did the army mark its equipment? General George Washington gave orders to address this issue on June 18th:
to prevent the embezzlement of the public tools, the Quarter-Master General shall cause all the Tools, of every kind, belonging to the United Colonies, or at any time purchased for them, to be marked, with the following brand or stamp.
What was the mark they were to use? CXIII.
If this were a simple Roman numeral, it would mean 113. But it seems like “C” was probably supposed to stand for “colonies” rather than being the Roman numeral for 100. Thus, the mark to be used for keeping people from stealing the army’s tools meant “Colonies 13.”
Source
“General Orders, 18 June 1776,” Founders Online, National Archives, accessed April 11, 2019, https://founders.archives.gov/documents/Washington/03-05-02-0017. [Original source: The Papers of George Washington, Revolutionary War Series, vol. 5, 16 June 1776–12 August 1776, ed. Philander D. Chase. Charlottesville: University Press of Virginia, 1993, pp. 31–33.]