Donny Williams didn’t spend his weekend in Washington walking around the Tidal Basin taking in the cherry blossoms. He was training people how to get arrested.

Williams, an environmental activist from Baltimore, taught a class in the nation’s capital on civil disobedience, part of a last-ditch campaign against the Keystone XL pipeline.

The sessions were held over the past two weekends in eight cities, including Chicago, New York and Los Angeles. While critics say they remain hopeful that President Obama will reject Keystone, the tutorials anticipate that a State Department-led review will find the project to be in the nation’s interest to build.

“We’re trying to create as much pressure as we can on President Obama,” Williams said. “We want to personalize this. This isn’t just the faceless masses.”

TransCanada Corp. applied more than five years ago for a permit to build the pipeline across the U.S.-Canadian border to link Alberta’s oil sands with refineries in Texas and Louisiana. Each new milestone leads supporters and opponents to marshal forces.

In January, the State Department released its final environmental review, which had prompted the submission of more than 1 ­million public comments. Next month marks the end of the period during which eight federal agencies, including the Environmental Protection Agency and Energy Department, have had a chance to comment on the project.

Secretary of State John Kerry will make a recommendation, weighing factors including Keystone’s environmental, economic and diplomatic impacts. Obama will then make the final call, ending years of a pitched battle over environmental protection, job creation and energy security.

Unions work for pipeline

Unions that support the pipeline are trying to match opponents by also increasing pressure. The Laborers’ International Union of North America, which represents the construction workers who would build Keystone, last week sent letters to 27 House Democrats, criticizing their opposition. Other letters went to union members in their members’ districts.

“These so-called ‘friends’ of ours are destroying good- paying work opportunities with family-supporting benefits, at a time when LIUNA members are trying to put food on their tables, keep roofs over their heads, and maintain middle-class lifestyles,” the letter states.

Meanwhile, 11 Senate Democrats, including five up for re- election, sent Obama a letter last week urging he approve Keystone.

Nearly 100,000 opponents have committed to risking arrest to show their views on Keystone, which would carry a carbon- heavy type of crude.

Scott Parkin, an activist at the Rainforest Action Network, a San Francisco group that describes its mission as “environmentalism with teeth,” said the pledge of resistance was modeled after civil disobedience actions against human rights abuses in Central America in the 1980s.