Unlike his more famous contemporaries, whose reputations grew with the times, Indiana's work fell by the wayside. Part of the problem was that he withdrew from New York (he currently lives in Maine), which meant he was no longer a part of the scene. However, during Indiana's prime in the 1960s, his work contributed to the era's dialogue of imagery derived from everyday life, taking its cue from street signs. You might say that Indiana created paintings that were actual signs in their own right. For instance, when he painted a work that literally said, "Yield, Brother," he called to mind the famous comments about the paintings of Jasper Johns -- "Is it a picture of a flag or an actual flag?" and "Is it a picture of a target or an actual target?"

Indiana was also obsessed with numbers, frequently incorporating them into his work. He even created a work that paid homage to Charles Demuth's often-reproduced painting of the figure five. Indiana's strong graphic style was also in some ways a throwback to Stuart Davis. Yet, despite borrowing here and there, Indiana, to his credit, evolved a style that was unmistakably his own. He seemed well on the way to becoming a significant player. Then, in 1966, he created his "Love" series and a promising career turned into a nightmare.

In 1970, the letters "L" and "O," balanced on top of the letters "V" and "E," became the indelible logo of the wildly successful book and movie, Love Story. But that was nothing compared with the 1973 U.S. Postal Service selection of the "Love" image for a postage stamp. The stamp went on to become (with the exception of certain Christmas stamps) the most popular stamp ever issued -- 333,000,000 were eventually sold. Unfortunately, the artist received only a standard $1,000 fee. Worse, as a result the image's incredible notoriety, his career was thrown off track -- he had become labeled as a commercial artist.

But despite the hostility of the art world, Indiana continued to work. He made progress, but it came at a high price. Gone was the magic and freshness of his breakthrough 1960s pieces. While Indiana took few risks with his new work, to his credit, he continued to create imagery with a strong visual punch. Thanks to a unique combination of high-pitched color and hard-edge shapes, his pictures are memorable -- they stay with the viewer.

In terms of his market, it had been dormant for years. Occasionally, a major painting would show up at auction and do well -- probably selling to a collector who needed to fill a gap in his collection of "Pop" holdings. However, in 2002, thanks to the championing of his work by Pascal de Sarthe, a private dealer based in Scottsdale, Indiana's market developed some momentum. A major museum exhibition opened in Shanghai. A deal was negotiated for a show of important early works at the uptown New York gallery, C&M Arts. Then, a second show of new works goes on view simultaneously at the Paul Kasmin Gallery in Chelsea. And both galleries are cosponsoring the installation on Park Avenue of a series of brightly colored sculptures in the shape of individual numbers from 0 to 9.

During the past November auctions, Indiana emerged as an artist to watch. Christie's post-war and contemporary day sale featured his 1968 painting, Love Wall: Black, Red, and Yellow, on its cover. The painting didn't disappoint as it blew past its $150,000-$200,000 estimate to sell for $295,500 -- a lot of money for a small work (24 x 24 in.). A larger painting, from the 1970s, Spring, split its $120,000-$180,000 estimate, bringing $141,500. There was also a pair of Indiana's three-dimensional works in the same sale. A two-foot-tall stainless steel Love sculpture, fabricated in 1997, brought $119,500 (est. $70,000-$90,000). The steel numeral, One, painted in Indiana's classic red and blue, just exceeded its high estimate to sell for $45,410. The auction record for an Indiana painting was set in May 2002 at Christie's when The American Sweetheart (96 x 48 in., 1958) sold for $614,500.

Right now, Robert Indiana is in the midst of a serious reevaluation by both the art market and art history. Obviously, a retrospective would offer an opportunity to sort out his achievement. Until that happens, it will be difficult to determine his true place in recent art history. However, with the current information that we have, if you ask yourself whether he is in the same league as Roy Lichtenstein, James Rosenquist and Claes Oldenburg, you would have to honestly answer "no." But does he belong in a hypothetical collection that would contain the above artists? Most definitely.