The aim of this paper is to provide an overview of Reagan’s fiscal Reform. It mainly involves an investigation of the legislative features of the Reform and of the underpinning economical theory. The study focuses on the impact of such a Reform on the economy. The paper comprises four main parts. The first part is devoted to the analysis of both Reagan’s fiscal policy actions in the 1980s and of the regulatory touch. In particular the first part investigates two main Laws, which reduced private marginal tax rates: the Economic Recovery Tax Act (1981) and the Tax Reform Act (1986). The second part introduces and analyses the so-called “Supply-Side Economics”, the main theory on which Reagan's Reform is based. Indeed the core of “Supply-Side Economics” was the “Laffer Curve” where tax rate cuts played a central role. The last two parts deal with the concrete effects of private marginal tax rate cuts. In particular, inequality and fiscal revenue. It also focuses on the criticisms against the Reform. Fiscal revenue is observed in a wider context. The paper first investigates the source of the deficits recorded during the 1980s. It relates these deficits to general government revenues and general government expenditures. Subsequently, general government revenues are broken down into their parts and the development of federal income tax revenue is carefully observed. Inequality is investigated through the Gini index. The paper touches briefly on the changes to the Gini index after Reagan’s two main fiscal Laws took effect. Furthermore, inequality is related to the progression of the tax system and then calculated through the Reynolds-Smolensky Index.