The Albright-Knox Art Gallery has been driven by an insatiable hunger for the new since the day of its founding in December 1862.

Its 150-year history is riddled with firsts:

The first museum in the world to host a photography show, in 1910.

The first museum to appoint a female director, Cornelia Bentley Sage, also in 1910.

The first to show Modigliani's work in America, in 1939.

Among the first to avidly collect what was then viewed as experimental work by abstract expressionist masters Willem de Kooning, Jackson Pollock, Mark Rothko and Clyfford Still.

From its founding as the Buffalo Fine Arts Academy, the Albright-Knox has forged a staunch tradition of being radically progressive. It seems like a contradiction: How could an institution retain the support of its community while constantly pushing the boundaries of what that community considers acceptable? How could a gallery of modest means, in a city on the outer orbit of the art world, amass one of the most impressive collections of 20th century art anywhere in the world?

The answer: Not without risk, not without luck and under the constant threat of controversy.

The Albright-Knox has never been far from criticism, whether for its passionately debated purchase of Picasso's painting "La Toilette" in 1926, its decision to sell off hundreds of premodern works from its collection in 2007 or its installation of Nancy Rubins' explosive canoe sculpture on its west lawn this summer.

The Rubins installation carried certain echoes of the gallery's establishment of its then-radical "Room of Contemporary Art" program in 1939, for the display of new works "on loan." After the dust settled, it placed this grand gallery in the City of Buffalo in a unique position to continue its progressive tradition of seeking out the best and most challenging contemporary art -- even as it is being created.

Occasionally, gallery directors who were not comfortable dwelling so close to the edge of popular taste have tried to lead the institution to safer ground, as when Edgar Schenck purchased the classical bronze sculpture known as "Artemis and the Stag" in 1953.

But future administrations, like the one now led by Louis Grachos, answered by setting the gallery back on its progressive -- and sometimes unpopular -- path. Thus it was, in 2007, that Artemis and some 200 other premodern objects made a dramatic exit from the gallery's stage and bolstered its endowment for buying new work by nearly $70 million.

So the history of the gallery has gone, in an ebb and flow of head-spinning progressivism marked by brief periods of conservative reaction. And though there have been missteps along the way, the gallery's past is a 150-year arc always bending sharply toward the new.

"The Long Curve," a term taken from a statement by the late Buffalo-born gallerist Martha Jackson about the time it takes for contemporary art to gain popular traction, serves as the title of the first of three exhibitions celebrating the gallery's sesquicentennial over the coming year. The show opened Friday and runs through March 4.

Here we present, in roughly chronological order, a few selected works of many dozens of stellar pieces (not all of which appear in the current exhibition) that represent the evolution of the Albright-Knox across its first century and a half and point to what the next 150 years might hold.