Extending 36 miles from Piscataqua Bridge in Durham to the Merrimack River in East Concord, the First New Hampshire Turnpike was originally a toll road. The first of more than 80 New Hampshire turnpikes built by private corporations in the nineteenth century, it was the only one connecting Portsmouth, the state's seaport, with the interior settlements. Chartered in 1796, the corporation began to build the road about 1801. Much of the present Route 4 follows the four rod (66 foot) right-of-way of this first turnpike.