(CN) - No major legal challenges to voting procedures were reported on an Election Day that saw record turnout of 148.2 million - 64.1% of registered voters - the highest percentage in 100 years, according to preliminary reports. The closest major race was in Minnesota, where Republican incumbent Sen. Norm Coleman declared victory over Democrat Al Franken, though Coleman's 726-vote margin - 0.03% of votes cast - will trigger a mandatory recount.
Secretary of State Mark Ritchey said the recount will not begin until mid-November and may not be completed until December.
The highest percentage of U.S. voter turnout in history was 66%, in the presidential election of 1908. Tuesday's turnout percentage appears to be the 2nd highest ever, eclipsing by far the 2004 turnout of 55.3% and 122.3 million voters.
Tuesday's turnout was 0.1% higher than in the Kennedy-Nixon nail-biter in 1960.
In the record year of 1908, 14.1 million Americans voted as William Howard Taft defeated William Jennings Bryan.