As free speach is guaranteed by the constitution, various media outlets legally publishing articles which are not based on facts have been established in the US. Furthermore, disinformation can be spread via social media as easy as in other countries.
According to my perception, factchecking organizations are more present in public than in Germany - despite or even because of lesser personal rights. Especially in Washington DC we met with different associations fostering media transparency.
Benefitting from lower data security policies in the US, the associations publish guidelines on how to recognize disinformation, create Twitter campaigns to reveal hoaxes or simply check the accuracy of press releases and social media activities.
The US government is also interested in transparency - at least regarding the foreign lobbyists who want to influence US policies. In 1938 the Foreign Agents Registration Act (FARA) was introduced in law. External contractors to foreign embassies as well as corporate lobbyists working in the US must be registered as foreign agents. In addition, all lobbying investments have to be disclosed.
There are several databases you can use for searching documents concerning the FARA legistlation. One of them is called Foreign Lobby Watch. You just need to enter a keyword to see how persons or companies are related to FARA. This tool was shown to us by the Center for International Policy.