Houlton, Maine, February 16, 1861, pair of 1¢ 1857 Type V stamps pays the 2¢ line office rate to Upper Woodstock, New Brunswick. Marked "PAID 2" and with the Houlton Maine "U. STATES." in arc exchange office marking. Three line office rate covers are recorded franked with 1¢ 1857 stamps.

The rarest of all cross border rates is the special 2¢ rate between adjacent exchange offices located not more than 5 miles apart. This rate is sometimes referred to as the "line office rate." As Houlton, Maine and Woodstock, New Brunswick are more than 5 miles apart, the line office rate originally did not apply to these offices. The line office rate was later extended to apply to mail between Houlton and Woodstock.