Excerpts from an NY Times article on Paul Kasmin gallery site:

Once a downtown art-world insider, Mr. Indiana, who invented the Love logo in 1964 ... lives ... in a four-story Victorian building stocked with his Love artworks in various forms in nearly every room. ... There are ... a startlingly wide range of Love merchandise... stacked to the ceiling with ... untold reproductions and unauthorized copies of his Love logo.

In 1964, the year he moved from Coenties Slip to the Bowery, Mr. Indiana designed the Love graphic for a Christmas card for the Museum of Modern Art. The logo took off, and in May 1966 he had a whole show of variations on the theme at the Stable Gallery in Manhattan.

The graphic became central to the 1960's visual vocabulary, appearing on clothes, jewelry, towels and rugs. The 1973 postage stamp with the logo was one of the best-selling stamps ever, though Mr. Indiana said he received only $1,000 for the design. (He had failed to copyright the logo, and so did not profit as it appeared on countless coffee cups and T-Shirts.) The logo did not endear Mr. Indiana to the art establishment, and his star faded in inverse proportion to the success of Love.