NEW YORK -- Nearly 38 million Americans watched inauguration coverage of President Barack Obama on Tuesday, the most popular inauguration day on television since Ronald Reagan took office in 1981.

Nielsen Media Research said Reagan's 41.8 million remains the record. Obama more than doubled the 15.5 million viewers who watched George Bush's second inauguration four years ago.

The ratings figure was an average number of people watching at any point from 10 a.m. to 5 p.m. EST. Viewership spiked during the noon hour when Obama was taking the oath of office and delivering his inaugural address.

During the 11 a.m. to 2 p.m. period, NBC captured the largest audience -- an estimated 10.4 million viewers, Nielsen said. ABC had 10.1 million and CBS had 7 million. CNN, with 6.9 million, narrowly missed beating CBS during those three hours but did during the 10 a.m. to 5 p.m. period. Fox News Channel had 4.4 million and MSNBC 2.6 million viewers between 11 a.m. and 2 p.m., Nielsen said.