Internet net adoption at home peaked in 2004

Check out this chart on the Pew Center for the Internet and American Life's web site.

Along with age, educational attainment represents one of the most pronounced gaps in internet access. Some 43% of adults who have not completed high school use the internet, versus 71% of high school graduates—and 94% of college graduates. Household income is also a strong predictor of internet use, as only six in ten (62%) of those living in households in the lowest income bracket (less than $30,000 per year) use the internet, compared with 90% of those making at least $50,000-74,999 and 97% of those making more than $75,000.6 Educational attainment and household income continue to be strongly correlated not only with internet adoption, but also with a wide range of internet activities and ownership of a number of devices.
The ways in which people connect to the internet are also much more varied today than they were in 2000. As a result, internet access is no longer synonymous with going online with a desktop computer:

Currently, 88% of American adults have a cell phone, 57% have a laptop, 19% own an e-book reader, and 19% have a tablet computer; about six in ten adults (63%) go online wirelessly with one of those devices. Gadget ownership is generally correlated with age, education, and household income, although some devices—notably e-book readers and tablets—are as popular or even more popular with adults in their thirties and forties than young adults ages 18-29.
The rise of mobile is changing the story. Groups that have traditionally been on the other side of the digital divide in basic internet access are using wireless connections to go online. Among smartphone owners, young adults, minorities, those with no college experience, and those with lower household income levels are more likely than other groups to say that their phone is their main source of internet access.
Even beyond smartphones, both African Americans and English-speaking Latinos are as likely as whites to own any sort of mobile phone, and are more likely to use their phones for a wider range of activities.