In 1836, Betts partnered with Samuel Pusey (a machinist) and began manufacturing railcars at a plant on West and Water Streets in Wilmington.

The facilities at this property were limited, so all the work forming iron plates, bars, and fasteners was done at their main shop on Front and West Streets.

The launch slipway was 200 feet long and could only accommodate vessels of 600 tons maximum, but this was deemed adequate for the needs of the time.

The first two hulls built by the company, the Ashland and Ocean, were two of the earliest iron steamboats to be constructed in the United States.

(Brown, 1951) During the Civil War the company won contracts for the construction of three monitors for the government (Patapsco, Saugus, and Napa).

Harlan & Hollingsworth thrived despite competition from Jackson & Sharp and other Wilmington yards, in part because of their diversified production of railroad car building and shipbuilding.

However, the Panic of 1873 and the death of Charles Morgan (their largest customer) induced the company to undertake government contracts again.

Despite this experience Harlan & Hollingsworth constructed three more torpedo boat destroyers for the Navy, the Stringham, Hull, and Hopkins.

Other notable vessels built by Harlan & Hollingsworth include Mischief, winner of the fourth America's Cup in 1881.

In the 1880s orders for ferries and coastal steamships started picking up again, so much that by the end of the 19th century, the company was the largest employer in Wilmington.