Henry Perrine Baldwin (August 29, 1842 – July 8, 1911) was an American businessman and politician on Maui in the Hawaiian Islands.

He supervised the construction of the East Maui Irrigation System and co-founded Alexander & Baldwin, one of the "Big Five" corporations that dominated the economy of the Territory of Hawaii.

He was named after Matthew LaRue Perrine (1777-1836), professor at Auburn Theological Seminary, from which his father had graduated shortly before his departure to the Hawaiian Islands.

Instead by 1863 he went to work for his brother David (also called Dwight Baldwin, Jr) who had started a small sugarcane farm.

He took a job as foreman (called luna) of the Waiheʻe plantation, owned by Christopher H. Lewers, under the management of Samuel Thomas Alexander.

In 1869, Baldwin and Alexander became business partners and bought 12 acres (49,000 m2) in the eastern Maui ahupuaʻa (ancient land division) called Hāmākua Poko.

Trying to adjust the rollers, his fingers got stuck in the cane grinder, pulling in his right arm, and he almost died before it could be turned off and reversed to free him.

Although the Hawaiian Islands have a 12-month growing season, a major problem with farming former dry forests was their wide extremes in precipitation.

[1] Alexander was more practical: his father had taught at Lahainaluna School where irrigation ditches had been used for small private gardens since the times of ancient Hawaii.

Alexander noticed the rainforests on the eastern (windward) side of the island and upper slopes of Haleakalā received much more rainfall.

William Harrison Rice had irrigated a small sugarcane plantation in 1856, but this system would supply 3,000 acres (1,200 ha).

Alexander arranged a survey, worked out financing from other planters to create the Hamakua Ditch Company and negotiated a two-year lease with the government of King David Kalākaua to build the project starting September 30, 1876.

Irish civil engineer Michael O'Shaughnessy designed the Koolau Ditch in 1904–1905 and some similar projects using technology developed for railroad tunnels.

[6] The irrigation projects became so profitable that the Alexander and Baldwin partnership was able to buy out other planters and enlarge their holdings.

Spreckels used his vast financial resources to bring German Engineer Hermann Schussler to build his own irrigation system from 1878 to 1880,[9] forming the Hawaii Commercial and Sugar Company.

[1] In 1888 he offered the foundation of the old Paliuli mill to his church, and a wooden frame building was built on the site where he lost his arm — his monument for answering his prayers.

[11] In 1888, Henry Baldwin and a few businessmen from Honolulu formed the Haleakala Ranch,[12] consisting of 33,817 acres (13,685 ha) on the slopes of the dormant volcano Haleakalā.

Baldwin took advantage of the lower land prices and built an irrigation project on Kauaʻi island called the Hanapepe ditch for the Hawaiian Sugar Company.

In 1903 he built another house called Maluhia at a higher elevation near Olinda, Hawaii surrounded by fruit trees.

[16] He was a member of the foreign affairs committee, and inherited his father's concern for public health, using his own money to fund better homes in the Kalaupapa Leprosy Settlement.

His sister Abigail Charlette Baldwin had married Samuel's brother William DeWitt Alexander (1847–1912) in 1861.

Harry was very active in politics, including serving as delegate to the United States House of Representatives from the Territory of Hawaii.

[17] Son William Dwight Baldwin was born October 25, 1873, graduated from Yale in 1897, and then Johns Hopkins Medical School in 1901.

He started work as a field worker and eventually became President of Kahului Railroad in 1910, and of the Hawaiian Commercial Company (HC&S) when Henry Perrine died.