Christopher Leonard, Simon & Schuster, 687 pages, $35. For over half a century, Charles Koch — the notoriously secretive multibillionaire from Wichita, Kan., and conservative political force — transformed Koch Industries from a midsize Midwestern company into a conglomerate exercising enormous influence over the American economy and public life. In "Kochland," Christopher Leonard has done an impressive job of breaking through the secrecy that the family has built and getting insiders as well as outcasts to talk. As a result, "Kochland" is the most definitive account yet of how one of America's richest and most powerful families amassed its fortune. For the most part, Leonard steers clear of the Kochs' influence on politics. He turns his efforts instead to exposing their sprawling business dealings and their strategy for building a corporate empire structured to avoid regulatory and public scrutiny. The Koch way, we learn, has had sweeping consequences for the American economy: crushing the power of unions and redefining the concept of regulatory compliance as it grew from $250 million in annual sales when Charles Koch took over in 1968 to $1.7 billion today. Leonard breaks down his management philosophy and profit initiatives. One example is the Flint Hills Pine Bend Oil Refinery in Rosemount and the possible steps the company skipped, feeling they weren't needed, that resulted in its $8 million fine for illegally dumping ammonia-laced wastewater in the Mississippi River and wetlands in 1999, and what might have gone wrong by putting profits above all else.