Google has dropped the specialized search landing page for searching U.S. federal, state and location information at what they called Uncle Sam Google Search at google.com/unclesam. As, when you visit google.com/unclesam you're now redirected to google.com/webhp.
Google has had Uncle Sam search way back when Google was a baby company as early as 1998. In fact, the logo for that search portal wasn't the one above but rather this one:
In 2006, Google relaunched a government search tool at usgov.google.com and kept the Uncle Sam search but now both are redirecting to Google's main home page.
Some people might remember Google Linux, Google BSD, Google Mac, Google Microsoft, the search engines that offered results related to operating systems. Google also created custom search engines for universities. All of these search engines are now gone as well.
A Google spokesperson has confirmed removing this vertical search feature and has given us a statement:
We';re no longer offering specialized search services at google.com/linux, google.com/microsoft, google.com/bsd, google.com/mac, google.com/about and google.com/unclesam. These services were established many years ago to offer search across a limited index of the web, which in the past was a better way to find this information. For e.g., google.com/linux was designed to help people find information from message boards and blogs about the Linux operating system. Today, search quality has advanced tremendously, and based on our analysis we'
e found that in most cases you're better off looking for this kind of specialized information using the regular Google search box, for example by typing [linux fedora upgrade]. We understand that some users were surprised by this change, so we apologize for not communicating more clearly in advance of redirecting these services to google.com. For more advanced search tips to restrict your search to particular sites and kinds of information, we recommend taking a look at our Help Center.
You can still find Google Linux, Google BSD, Google Microsoft and Google Mac in the Web Archive. Here's a Google Advanced Search page from 2000 that linked to the "topic-specific" search engines and a newsletter from Larry and Sergey that announced Google Government Search in June 1999:
This month you probably noticed that we had our "Uncle Sam" search off of our home page (It's the next best thing to the CIA) that is now housed on the "more Google" page under the title of "special searches." This search covers all the .mil and .gov domains. So if you are looking for something published by the government, this is the best place to start.
Back in 1998, Google's first homepage linked to Stanford Search and Linux Search.