On 1 May 2004, Poland joined the European Union. Together with nine other states, it became a full-fledged member of the European community. Today marks the 15th anniversary of these events and Poland’s EU membership is supported by a record 91%* of our country’s inhabitants. Europe is a place where we live and work. It is a place that we help to develop and one that helps us to develop!
https://poland.pl/politics/foreign-affairs/eu-our-place-for-the-past-15-years/