and the National League of Cities provided joint administrative support for the fledgling sister city movement until 1973. A 1974 study found that many early sister city relationships formed out of the post WWII aid programs to Western Europe. The relationships that endured, however, were based on cultural or educational reasons that developed lasting friendships. During the mid-1960s, city affiliations recognized that their diverse efforts needed coordination. In 1967, the Town Affiliation Association of the U.S. (already popularly known as Sister Cities International) was created. Entering new territories In 1979, the very first U.S. and People's Republic of China links were created. San Francisco made waves by forming a "friendship" relationship with Shanghai, China. Despite Cold War tensions, U.S. cities had already initiated sister city relationships with the Soviet Union in 1973. Programs at that time focused on basic urban problems such as water and sanitation, health, housing, education and transportation. Begun in 1977, the national Technical Assistance Program (TAP) worked to create training programs to increase employment, establish cooperatives and credit unions or to create appropriate small-scale industries. Development agencies realized that industrializing countries experienced the same urban problems as developed nations. The sister city movement provided a mechanism for communities to share their experiences and growing pains. TAP focused on a spiral out benefits system. For example, a city project to improve surface drainage would indirectly aid the urban poor. These citizens would gain better sanitation and possible employment from the project. The United States Agency for International Development (USAID) provided seed grant money for the project. In the mid-1970s, the Town Affiliation Association began the School Affiliation Program. Through this program, youth gained greater sensitivity toward other cultures and a broader global perspective. In one program, Oakland, California and Fukuoka, Japan spent a school year exchanging artwork and conducting workshops on the Japanese culture. Celebrating a 25th anniversary The Town Affiliation Association marked its 25th anniversary in 1981. By that time, 720 U.S. cities representing 85 million citizens were linked to over 1,000 communities in 77 nations around the world. In addition, the association's name evolved to its current form, Sister Cities International. During the 1980s, a focus on municipal twinning developed. Mayors began to focus on relationships that offered technical assistance in municipal development. Similar to TAP, these exchanges worked on citywide issues such as solid waste management, urban planning, emergency response training and emergency management.