The United States Government has a long history of creating and making publicly available data which promote the public good. Many of these data are discoverable through data.gov; however, many more datasets and data portals are hosted on government websites and discoverable through government partner databases, such as USDA's Economics, Statistics and Market Information System hosted through Cornell University or ICSPR.
Federal government websites are often changed reflecting the priorities of the current administration. But, sometimes you want some information or data on a previous website. The general websites can usually be found through the End of Term Crawl. However, discoverability and searching is more challenging.
If you know the URL for a government website that is now 404, use the Internet Archive's Wayback Machine.
If you want to find URLs through a search engine (instead of the google/bing tracking URLs), a good search engine to use is DuckDuckGo. An added bonus to being able to just copy a URL is DuckDuckGo doesn't track you.