President Franklin D. Roosevelt signed the Reciprocal Trade Agreements Act (RTAA) in 1934. It gave the president the power to negotiate bilateral and reciprocal trade agreements with other countries and allowed Roosevelt to liberalize U.S. trade policy around the world. It is generally attributed that it sounded the era of liberal trade policy that continued during the 20th century.  Democrats voted much more in favor of trade liberalization than Republicans, but were not consistent in their preferences. Mp Henry Rainey (D-IL) and members of Roosevelt`s government, Rexford Tugwell, Raymond Moley and Adolf Berle, were skeptical of tariff reductions during the Depression. However, the government decided to use a Democratic-controlled congress and presidency to impose the RTAA. In 1936 and 1940, the Republican Party ran on a platform to lift tariff reductions guaranteed under the RTAA. But when they reclaimed Congress in 1946, they did not act to remove tariffs. In the years since the adoption of the RTAA in 1934, the economies of Europe and East Asia had been decimated by the violence of World War II, which left a huge global production gap filled by American exporters.  During the war, the United States had the highest positive balance in its history. Republican preferences for tariffs began to shift as exporters in the home districts began to benefit from stronger international trade.
In the 1950s, there was no statistically significant difference between Republicans and Democrats on customs policy, a change that has lasted ever since.  From then on, during the rounds and negotiations on the free trade area at the GATT (later the WTO), the President was granted the negotiating powers of non-tariff measures in the respective legislation, such as the Trade Act of 1974, but the power to reduce tariffs in general was similar to that of the RTAA. Secretary of State during the presidency of the FDR; reciprocal trade policy for new drug dealers, as well as low tariff rates; led to the passage of the Reciprocal Trade Agreements Act of 1934; he also believed in good neighborism. Hull was awarded the Nobel Peace Prize in 1945 for its role in the creation of the United Nations, and recipiement was an important principle of trade agreements negotiated under the RTAA, as it encouraged Congress to reduce tariffs. As more and more foreign countries have entered into bilateral tariff reduction agreements with the United States, exporters have been more encouraged to promote Congress in favour of even lower tariffs in many sectors.  RTAA`s innovative approach freed Roosevelt and Congress from breaking this trend of tariff increases. It has linked U.S. tariff reductions to reciprocal tariff reductions with international partners. It also allowed Congress to approve tariffs by a simple majority, unlike the two-thirds majority needed for other contracts. In addition, the President had the power to negotiate the terms.
The three innovations in trade policy have created the political will and feasibility of a more liberal trade policy.  Between 1934 and 1945, the United States signed 32 reciprocal trade agreements with 27 countries.  In addition, the conclusion of the General Agreement on Tariffs and Trade was taken by the Authority under the RTAA. As more and more U.S. industries began to benefit from tariff cuts, some of them began campaigning with Congress for lower tariffs. Until RTAA, Congress had been mainly pressured by industries that wanted to create or increase tariffs to protect their industry. This change has also helped to maintain many of the benefits of trade liberalization.