1994–2001
Main article: Online diary

Brad Fitzpatrick, an early blogger.
The modern blog evolved from the online diary, where people would keep a running account of their personal lives. Most such writers called themselves diarists, journalists, or journalers. A few called themselves "escribitionists". The Open Pages webring included members of the online-journal community.
2001–2004
Several broadly popular American blogs emerged in 2001: Andrew Sullivan's AndrewSullivan.com, Ron Gunzburger's Politics1.com, Taegan Goddard's Political Wire, Glenn Reynolds' Instapundit, Charles Johnson's Little Green Footballs, and Jerome Armstrong's MyDD — all blogging primarily on politics (two earlier popular American political blogs were Bob Somerby's Daily Howler launched in 1998 and Mickey Kaus' Kausfiles launched in 1999).
By 2001, blogging was enough of a phenomenon that how-to manuals began to appear, primarily focusing on technique.
2004–present
In 2004, the role of blogs became increasingly mainstream, as political consultants, news services and candidates began using them as tools for outreach and opinion forming. Even politicians not actively campaigning, such as the UK's Labour Party's MP Tom Watson, began to blog to bond with constituents.