President Obama's re-election campaign reached its one-year anniversary today, and marked the milestone by underscoring the high points in what has become a far-reaching grassroots organizing operation.

On April 4, 2011, Obama emailed supporters to say that he had officially filed papers to run for a second term.

"In the coming days, supporters like you will begin forging a new organization that we'll build together in cities and towns across the country," he wrote at the time. "And I'll need you to help shape our plan as we create a campaign that's farther reaching, more focused  and more innovative than anything we've built before."

One year later, the organization is firmly established and growing, as documented in a new Obama campaign web feature and email from campaign manager Jim Messina.

Some data points highlighted by Team Obama:

- Offices in all 50 states  (a progression map shows where they have popped up over the past year; note the concentrations in key battlegrounds)

- 28,571 organizing events held since last April

- 1.8 million total donors

- More donors in the first quarter of 2012 than in any single quarter previously

- 118,000 donations on March 31, just before the Federal Election Commission monthly deadline, was the most donors ever in a single day

"Today's an important day in this race for another reason," Messina writes in the email appeal. "Mitt Romney won three more primaries last night, and an increasing number of folks in the Republican Party establishment are calling for the GOP nominating process to come to an end.

"A number of states still haven't voted, and the race on their side won't be over officially for several weeks or even months," he said, "But the reality is that we're very close to the start of what's effectively a general election."

The shift in the race has been on full display the past few days as Obama and Romney attack each other and their political platforms more directly.

At this juncture, Obama holds a financial edge, with more than $84.7 million cash on hand through February compared with Romney's $7.3 million.  The Obama campaign also holds an edge with its paid staff - employing more than 530 people compared with Romney's team of   100.  (As Romney moves closer to clinching the nomination, however, his resources will significantly grow.)

The Obama campaign's milestone didn't pass without drawing a partisan attack, however.

Republican National Committee Chairman Reince Priebus used the opportunity to mock the president's re-election message and his record over the past three and a half years.

"One year ago today, President Obama declared his campaign for re-election, and in the past year, he's made it clear to America that he has forever abandoned 'hope and change,'" Priebus said in a statement. "Instead, he's counting on fear and division to get re-elected. With no record to run on, he's spent his time desperately attacking his opponents and blaming others for his failures."