The Family Research Council, which co-sponsored the March for Marriage, has posted a video calling out the media for under-reporting the march and for under-estimating its numbers:

Some are noting the lack of mainstream coverage of our march for marriage including one blogger who attended and posted their own photos to prove it was happening. Many outlets, however, did cover the thousands who showed up to show their strong support for marriage! Here are a few.

ABC 7 "Thousands march on mall":

Thousands marched from the National Mall to the U.S. Supreme Court to say that marriage should be between a man and a woman.

“What God has instituted man does not have the power, right or authority to alter,” says Lalita Smith of Nashville. “We need to not play with the thing God has instituted.”

The marchers came from all over the country, from pro-family and church organizations.

Politico:

Opponents of same-sex marriage walked in the “March for Marriage,” organized by the National Organization of Marriage, eventually coming down to the street in front of the Supreme Court.

Catholic News Service:

Thousands of people who gathered at one end of the National Mall March 26 in support of traditional marriage took their message to the U.S. Supreme Court as they walked and held aloft placards with signs saying: "Kids do best with a mom and dad."

The court began hearing oral arguments that morning on the constitutionality of California's Proposition 8, the law banning same-sex marriage, the day before hearing oral arguments in a challenge to the federal Defense of Marriage Act.

Hours before and up to the minute the hearings began, the street in front of the court was filled with protesters on both sides of the same-sex marriage issue. Those in support of traditional marriage came to Washington with church or parish groups from nearby or had traveled alone or with one or two others from states across the country, including Massachusetts, New York, Minnesota and Florida.

When the groups dispersed, those supporting traditional marriage continued their march back to the rally point on the mall where numerous speakers echoed the message that marriage should not be redefined.

National Review Online:

Families gathered on the mall after marching to the Supreme Court to insist that the Court at the very least leave the future of marriage policymaking to the people rather than judicial fiat. Speakers from the National Organization for Marriage, the Heritage Foundation, Concerned Women for America, and others were in an encouraging mode. One got the sense that this was but a beginning of a conversation, a bit of a wake-up call.

Catholic World Report:

“Marriage is not about what adults want; it’s about what children need,” Teetsel said.

The march, which took place under clear but chilly skies, was held as the high court considered the constitutionality of California’s Prop. 8. On Wednesday, it hears oral arguments about one section of the federal Defense of Marriage Act (DOMA).

Marchers—estimated by organizers to be about 10,000 people—walked with placards and banners past the U.S. Capitol and the U.S. Supreme Court, where same-sex “marriage” supporters listened to a rally of their own and packed the sidewalks between the court and capitol.