PORTLAND — Exhibitions of works by John Marin, one of America’s most important painters at the time of his death in 1953, have focused on his early work — coloring popular understanding of his life’s work.

The Portland Museum of Art will shift attention to the latter part of his career, between 1933 and 1953, with “John Marin: Modernism at Midcentury,” featuring 54 paintings, drawings and watercolors.

The exhibit, the first in-depth examination of the artist since 1990, will showcase Marin as an artist committed to developing a modern visual language of landscape and place in an era preoccupied with complete abstraction.

Based in New York and New Jersey, Marin followed a path time-honored by artists to coastal Maine. Unlike an earlier generation, however, he brought his modernist eye to Maine’s landscape. He initially painted near mid-coast Small Point in 1914, but in 1933 began summering in remote Cape Split. This move farther north heightened the painter’s commitment to a raw, unspoiled landscape.

By the time he took up residence along the coast of Maine, Marin had begun to work in oil on canvas alongside his staple of watercolor. The medium of oil, with its fluidity and texture, suited capturing not only the impact of the wind, sun and rain on the sea but the intense blue and green colors of its waters.

While the sea became a focus of Marin’s work after 1933, he would never forgo the New York skyline or the Ramapo hills and Saddle River of New Jersey. He continued to mine these sites for their vitality, but they became progressively nonrepresentational, employing geometric patterns and culminating in the 1950s in calligraphic, lacelike statements. Many of Marin’s oil paintings during this period were accompanied by stock frames, which he painted with loose, geometric shapes as an extension of the canvas.

Works in “John Marin: Modernism at Midcentury” are major loans from the Museum of Fine Arts in Boston, Museum of Modern Art in New York and the National Gallery of Art in Washington, D.C., as well as museums and private collections throughout the country.

The exhibit will be on view from June 23 to Oct. 10.

The museum at Seven Congress Square is open 10 a.m. to 5 p.m. Tuesday, Wednesday, Thursday, Saturday and Sunday; and 10 a.m. to 9 p.m. Friday. Admission is $10 for adults, $8 for seniors and students with ID, $4 for youths ages 6-17 and free for children under 6. Admission is free from 5 to 9 p.m. Friday.