When Affirmative Action Was White describes the period from the depression to the aftermath of the second world war, Roosevelt's and Truman's administrations, focussing on federal policies and programmes in four areas affecting living standards and life chances: 1) relief, welfare, Social Security (state pensions); 2) "rules for work", minimum wages, union membership and benefits; 3) mobilisation and military service; 4) the G.I. Bill (benefits for veterans).

Katznelson argues that these national government interventions - essential to deal with global depression, world war and peacetime readjustment - produced a virtual social transformation, a middle-class welfare state, in which white and black Americans participated and benefited.  However, southern Democrats in Congress held the balance of power in the majority party and effectively, if figuratively, vetoed legislation that might destabilise the region's social order of racial segregation and exclusion.  To accommodate the "solid south", laws and programmes were deliberately designed to protect white interests and advantages, although ostensibly meant to be colour-blind. 

For example, Social Security and minimum wages excluded agricultural and domestic workers; three-quarters of African-Americans lived in the south where their employment was concentrated in agriculture and domestic service.  Where such indirect exclusion could not be written into legislation, Congress mandated decentralised administration, state and/or local, allowing covert discrimination e.g. in vocational training for veterans.  Private-sector providers often discriminated, north and south; e.g. mortgage lenders refused federally guaranteed loans to low-income veterans and on properties in disfavoured locations, relatively excluding more blacks than whites.  The effect was to deny African-Americans their fair shares of social and economic goods. The whole pie and every piece grew, but the relative size of the African-American piece diminished.  This is the "untold history of racial inequality"

Katznelson's purpose, not primarily historiographic, is to locate the history strategically on terrain, affirmative action, still contested today.   Positive discrimination or preferential treatment of African-Americans to redress past discrimination, particularly in education, employment and related fields, began in the mid-1960s.  Its career has been one of conflict and challenge, leading to Supreme Court decisions restricting its applications, disallowing race-based group preferential treatment, but allowing employers, universities, unions, etc. to take race into account in hiring, admitting, promoting individuals, under two conditions.  Action must aim to rectify specific historic racial injury, and for a public purpose sufficient to justify breaching the colour-blind rule, the equal protection guaranteed by the Constitution's 14th amendment.  Katznelson thinks that the disadvantages blacks suffered in the 1930s and 1940s, the obverse of a massive preferential resource distribution to whites, count as injuries which can be redressed, and count as racial because Congress excluded African-Americans deliberately, directly or indirectly, as its southern members demanded.

In conclusion Katznelson offers some examples of affirmative action "that could yield both tangible and symbolic compensation".  There is space here for one.  For the delayed entry into Social Security the "excluded could be identified and they, or their heirs, could be offered one time grants" required to be deposited "into designated retirement funds."   Whether a sufficient public purpose could be found in such wider applications is moot, but it is doubtful Congress would sanction or fund such programmes.  Katznelson doesn't discuss the politics of affirmative action today or tomorrow, the book's major flaw, an absence of practical political science.

This book is rich historiographically; it brings together topics and disciplines too often isolated and offers a trenchant public policy discussion informed by a moral concern for social justice.  It will reward students of history, the political economy of race, social policy and administration, and more.  There is no general bibliography, but 43 pages of notes provide numerous references and much pertinent information.