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COLLECTION Identifier: gra00030

Thaddeus William Harris papers

Scope and Content

The Harris collection is divided into three series: Correspondence, Botanical Lectures, and Notebooks.

Correspondence consists of about 20 letters to Harris which were bundled by subject, some with notes pertaining to subject -- general botanical, hemp, Lycopsis virginica and Myosotis arvensis, soybeans, squashes and entomology. Subject headings are not in Harris’s handwriting. There are also 6 letters which were found among Harris’s lecture notes and moved to this series.

Materials in the Botanical Lectures series were found together and consist of instruction notes, charts and illustrations, lecture notes, and other loose botanical notes. They have been loosely grouped by subject.

There are six botanical notebooks. Four appear to pertain to unfinished work on common flowering plants, one contains an index to some works of Linnaeus, and one contains brief descriptions of plants.


  • Creation: circa 1818-1852


Conditions Governing Access

The collection is available by appointment for research. Researchers must register and provide one form of valid photo identification. Please contact for additional information.


0.3 linear feet (14 folders)


Thaddeus William Harris was born on November 12, 1795, in Dorchester, Massachusetts, the son of Mary Harris and Thaddeus Mason Harris, who was a Unitarian minister. Harris entered Harvard College in 1811 and received a bachelor’s degree in 1815. He went on to study at the medical school, earning a medical degree in 1820. Around this time, Harris became interested in entomology through his contact with Harvard professor William Dandridge Peck.

Harris went into medical practice with Amos Holbrook in Milton, Massachusetts. In 1824 he married Holbrook’s daughter, Catherine. They had twelve children between 1826 and 1849, one of whom died in infancy.

Harris left medicine to accept an appointment as librarian at Harvard College in 1831, a position he held for 25 years. That year he also prepared a catalogue of insects for Edward Hitchcock's “Report on the Geology, Mineralogy, Botany and Zoology of Massachusetts.” From 1837 to 1842 he lectured on natural history at Harvard while the natural history professorship was vacant and he also taught a private class on entomology. He had hoped for a permanent appointment to the professorship but it was given to Asa Gray in 1842.

Harris built a carefully arranged and described insect collection, compiled indexes to major works on entomology, and published approximately 100 articles on insects and insect-related diseases. He was also particularly interested in botany, though his achievements in the field never reached the level of those in entomology. He did publish several articles in “New England Farmer” and prepared a monograph on Cucurbitaceae which was never published.

In his later years administration of the library took up most of Harris’s time and he was forced to give up natural history study. He suffered an attack of pleurisy in November 1855 and never fully recovered. Harris died in Cambridge, Massachusetts January 16, 1856.


Higginson TW. 1869. Memoir of Thaddeus William Harris. Boston: Boston Society of Natural History.


This collection is organized into three series. Series I. Correspondence; Series II. Botanical Lectures; Series III. Notebooks.


This collection was given to the Gray Herbarium by Elizabeth Harris, though Samuel Henshaw, on May 23, 1924.

Processed by:

Lynn McWhood

January 1982

Harris, Thaddeus William, 1795-1856. Thaddeus William Harris papers, circa 1818-1852: A Guide.
Botany Libraries, Gray Herbarium Library, Harvard University.
Description rules
Language of description

Repository Details

Part of the Botany Libraries, Gray Herbarium Library, Harvard University Repository

The Harvard University Herbaria houses five research libraries that are managed collectively as the Botany Libraries. The Gray Herbarium Library specializes in the identification and classification of New World plants with emphasis on North American plants. The Archives of the Gray Herbarium houses unique resources including personal papers, institutional records, field notes and plant lists, expedition records, photographs, original artwork, and objects from faculty, curators, staff, and affiliates of the Gray Herbarium.

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