While teaching in 1866 at Willamette University under the supervision of Thomas Milton Gatch, recent graduate Joseph K. Gill purchased a school supply company in Salem, Oregon, and opened a small bookstore there in 1867.
 In 1868, Gill built a new, larger store with partner C.F. Yeaton in Salem, and in 1870 he sold his business to Yeaton and moved to Portland.
There he formed a partnership with George A. Steel and purchased the Harris and Holeman stationery store at the corner of Front and Washington Streets.
Gill and Steel marketed a variety of books and office supplies.
The company moved in the mid-1870s, opening at First and Oak to be near the Ladd and Tilton Bank at First and Stark.
Steel retired in 1878, and the firm was renamed J.K. Gill and Company.
The company briefly split its wholesale and retail operations, remaining at First and Oak under the name W.B. Ayer and Co. and opening the J.K. Gill wholesale warehouse near the Skidmore Fountain.
In 1888 the two branches of the company were reunited under the name J.K. Gill, and in 1893 the company moved to the former Masonic Lodge at Third and Alder.

In 1922 the company began construction of a new headquarters at Fifth and Stark under the direction of architects Sutton & Whitney.
Estimated cost of the eight-story building was $300,000, and total cost including land and furnishings was about $600,000.
At that time, J.K. Gill was considered the largest distributor of books in the Pacific Northwest and the largest business of its kind in any city in the United States the size of Portland.

From at least the 1880s, publication of books, lithographs, and maps was also part of the business.
Gill's Dictionary of the Chinook Jargon was a standard reference for trappers and traders doing business among the Chinook people.

After the death of founder Joseph K. Gill in 1931, the company continued to grow.
In the 1960s a shift away from downtown stores began, and by 1990 the chain's stores were located mostly in shopping malls.

Ownership of the company remained with the Gill family until 1970, when the firm was sold to Young & Rubicam.
 At that time, there were 11 stores in Oregon and Washington and $13.8 million in annual sales.
 Young & Rubicam expanded the business, and by 1979 there were 36 stores in three states and annual sales exceeded $40 million (equivalent to $141 million in 2019).
J.K. Gill was acquired by Bro-Dart Industries in September 1980, becoming a subsidiary of that company.
 At the time, the company employed about 500 people and its total of 36 stores comprised 27 in Oregon and Washington, and nine in California.
 By early 1984, J.K. Gill had added two stores in Arizona, and had 13 in Oregon, 15 in Washington, and an unspecified number in California.

The company's 8,000-square-foot (740 m²) flagship store in downtown Portland, in the J.K. Gill Building at 5th and Stark, closed in 1991.
 (Multnomah County began leasing space in the J.K. Gill Building in 1978 and purchased the nine-story building in 1988, for use by offices of the county's Health Department.)

In the 1990s, amid increasing competition from larger, national companies, Gill's was forced out of business.
Its last stores closed in 1999.
While teaching in 1866 at Willamette University under the supervision of Thomas Milton Gatch, recent graduate Joseph K. Gill purchased a school supply company in Salem, Oregon, and opened a small bookstore there in 1867.  In 1868, Gill built a new, larger store with partner C.F. Yeaton in Salem, and in 1870 he sold his business to Yeaton and moved to Portland. There he formed a partnership with George A. Steel and purchased the Harris and Holeman stationery store at the corner of Front and Washington Streets. Gill and Steel marketed a variety of books and office supplies. The company moved in the mid-1870s, opening at First and Oak to be near the Ladd and Tilton Bank at First and Stark. Steel retired in 1878, and the firm was renamed J.K. Gill and Company. The company briefly split its wholesale and retail operations, remaining at First and Oak under the name W.B. Ayer and Co. and opening the J.K. Gill wholesale warehouse near the Skidmore Fountain. In 1888 the two branches of the company were reunited under the name J.K. Gill, and in 1893 the company moved to the former Masonic Lodge at Third and Alder.
In 1922 the company began construction of a new headquarters at Fifth and Stark under the direction of architects Sutton & Whitney. Estimated cost of the eight-story building was $300,000, and total cost including land and furnishings was about $600,000. At that time, J.K. Gill was considered the largest distributor of books in the Pacific Northwest and the largest business of its kind in any city in the United States the size of Portland.
From at least the 1880s, publication of books, lithographs, and maps was also part of the business. Gill's Dictionary of the Chinook Jargon was a standard reference for trappers and traders doing business among the Chinook people.
After the death of founder Joseph K. Gill in 1931, the company continued to grow. In the 1960s a shift away from downtown stores began, and by 1990 the chain's stores were located mostly in shopping malls.
Ownership of the company remained with the Gill family until 1970, when the firm was sold to Young & Rubicam.  At that time, there were 11 stores in Oregon and Washington and $13.8 million in annual sales.  Young & Rubicam expanded the business, and by 1979 there were 36 stores in three states and annual sales exceeded $40 million (equivalent to $141 million in 2019). J.K. Gill was acquired by Bro-Dart Industries in September 1980, becoming a subsidiary of that company.  At the time, the company employed about 500 people and its total of 36 stores comprised 27 in Oregon and Washington, and nine in California.  By early 1984, J.K. Gill had added two stores in Arizona, and had 13 in Oregon, 15 in Washington, and an unspecified number in California.
The company's 8,000-square-foot (740 m²) flagship store in downtown Portland, in the J.K. Gill Building at 5th and Stark, closed in 1991.  (Multnomah County began leasing space in the J.K. Gill Building in 1978 and purchased the nine-story building in 1988, for use by offices of the county's Health Department.)
In the 1990s, amid increasing competition from larger, national companies, Gill's was forced out of business. Its last stores closed in 1999.
J. K. Gill Company