The steamer Sir John Harvey operated as packet between Boston, Massachusetts, and Halifax, Nova Scotia, from July 1852 through February 1853. The United States and Nova Scotia negotiated a postal agreement that was scheduled to take effect December 1, 1852, by which mail was to be exchanged by the Sir John Harvey. Although Nova Scotia delivered mail to the United States pursuant to the proposed postal agreement, the United States did not send any mail to Nova Scotia pursuant to the proposed agreement. Additionally, the United States does not appear to have recognized the agreement. Only three sailings occurred pursuant to the proposed agreement, which was the only mail service at the treaty rate between the United States and the Province of Nova Scotia prior to the Canadian Confederation in 1867. The letters carried from Nova Scotia to the United States by the Sir John Harvey during this period were marked with the Nova Scotia scroll marking, the only Nova Scotia exchange office marking used for cross border mail. Only four covers with this marking are reported.

Halifax, Nova Scotia, February 15, 1853, unpaid letter rated 10¢ due to New York.  Endorsed "per Steamer Sir John Harvey."  Carried on the third and final contract sailing of the Sir John Harvey.  One of four recorded covers with the the Nova Scotia Scroll Exchange Marking. 

Ship letter dated September 14, 1852.  Carried on a non-contract sailing of the Sir John Harvey.  Enters the mails at Boston on September 16, 1852, where it was rated 7¢ due as a ship letter (5¢ for an unpaid letter for a distance of under 300 miles plus a 2¢ ship letter fee).    

Another ship letter carried by the Sir John Harvey.  Datelined Halifax, November 20, 1852.  Carried on the last non-contract sailing of the Sir John Harvey.  Enters the mails at Boston on November 26, 1852, where it was rated 7¢ due as a ship letter upon arrival in Boston (5¢ for an unpaid letter for a distance of under 300 miles plus a 2¢ ship letter fee).  Ex Blake.