Welcome to CapBiz A.M., your morning primer on business news with a focus on Washington.

Come one, come all: More than 17 million Americans visited the nation’s capital last year, an all-time record and a 3.1 percent increase over the year before, District officials announced Tuesday. And those tourists spent plenty of money while they were in town. (CAPBIZ)

Seeing green: Only a few blocks from the White House, 801 17th Street Northwest boasts the highest possible environmental rating for a commercial building – and now, it boasts the highest ever price paid for a D.C. office building, too. (CAPBIZ)

Sticking around: Pepco Holdings CEO Joseph Rigby, who announced plans to step down in January, will remain with the company longer than expected to help oversee the merger with Exelon Corp. That means his $14.1 million exit check will have to be renegotiated, too. (WBJ)

Brown means business: Maryland gubernatorial hopeful Anthony G. Brown has outlined a $112 million package of proposals intended to “ensure that Maryland is a great state to do business,” including a sweeping overhaul of the state’s tax system. (WP)

Massive offering: China’s Alibaba Group has filed to raise $1 billion in a long-awaited initial public offering likely to have ripple effects across the Internet. It will be the technology sector’s largest market debut since Twitter.

Bayer’s the buyer: Germany’s Bayer has agreed to buy Merck & Co.’s consumer care business for $14.2 billion, adding the likes of Claritin, Coppertone and Dr. Scholl’s to the company’s already extensive lineup of non-prescription brands. (AP)

Office closed: Office Depot plans to shutter at least 400 stores across the country over the next two years as the company looks to consolidate its operations after acquiring rival OfficeMax – and investors are delighted with the decision. (REU)

Paging small businesses: Facebook is ramping up its efforts to attract advertising from small businesses, launching a new campaign with workshops in five cities to show business owners the nuts and bolts of using the social network as a marketing tool. (AP)

Closing the gap: The United States’ trade deficit narrowed in March as exports surged to the second highest level on record, according to the Commerce Department, led by an increase in sales of aircraft, autos and farm goods. (AP)

On Wall Street

After a strong start to the week, stocks moved sharply lower on Tuesday, weighed down by weak earnings from several U.S. companies, including Twitter. All eyes will be on Janet Yellen later this morning. (Get the latest updates here)

What’s on tap today

Gallup job creation index (8:30 a.m.)

Federal Reserve Chair Janet Yellen remarks (10 a.m.)

Working Women’s Luncheon: Women in Politics (11:30 a.m.)

House Small Business Committee hearing on veteran business programs (1:00 p.m.)

Cutting-edge technology company demo event at 1776 (6:30 p.m.)

Help: How to capture the most useful feedback about your company (FOR)

Follow: Alibaba, the Chinese e-commerce platform heading toward a historic IPO

Extra: Students at one local university are helping Google build its next smartphone. (WP)