At Waterville the P&K connected with the Androscoggin and Kennebec Railroad (A&K).

At North Maine Junction, the A&K connected with the Bangor and Piscataquis Railroad.

[1] In 1845 the year that the P&K was chartered, a law was enacted permitting both the P&K and A&K to consolidate under a new name.

The P&K and A&K did not merge until after the contentious section of the previous merger legislation was repealed on September 9, 1862.

The following month on October 28, 1862, the A&K and P&K merged to form the Maine Central Railroad.