NEW YORK (AP) - The drive by the Democratic-led House of Representatives to impeach President Donald Trump was the top news story of 2019, according to The Associated Press' annual poll.

Trump also figured in the second and third biggest stories of the year: the fallout over his immigration policies and the investigation by Special Counsel Robert Mueller into whether his election campaign coordinated with Russia.

But it was impeachment that was by far the top choice in the AP poll, a story that gained steam with each passing week after details emerged about a phone call in which Trump pressured the newly elected Ukrainian president to announce an investigation into his chief Democratic rival, former Vice President Joe Biden.

Congress held a series of nationally televised hearings during the inquiry, culminating with a party-line vote Wednesday evening to impeach an American president for the third time in U.S. history. The impeachment process laid bare the deep partisan divisions roiling American politics during the Trump presidency.

The selections for Associated Press story of the year were made by a panel of editors and managers from newspaper, TV station and AP newsrooms around the globe.

A year ago, the mass shooting at a high school in Parkland, Florida, - which killed 17 students and staff, and sparked nationwide student-led marches for gun control - was voted the top news story of 2018.

The first AP top-stories poll was conducted in 1936, when editors chose the abdication of Britain's King Edward VIII. Impeachment was also voted the top story of the year the last time it happened - in 1998 over the Bill Clinton-Monica Lewinsky scandal.

Here are 2019′s top 10 stories, in order:

TRUMP IMPEACHMENT: Led by House Speaker Nancy Pelosi, Democrats moved to impeach the president based on allegations that he abused the power of his office by enlisting a foreign government to investigate a political rival. The articles of impeachment also accused Trump of obstructing Congress' oversight like "no president" in U.S. history. But Democrats failed in their bid for a bipartisan action -- no Republicans in Congress broke with the president. Trump and Republicans repeatedly mocked the process as a "sham" and insisted he did nothing wrong.

IMMIGRATION: The Trump administration carried out sweeping new immigration enforcement measures in the face of a crisis that saw record numbers of migrant families arrive at the U.S.-Mexico border. Several immigrant children died after being held in U.S. custody, children were found living in squalid conditions at cramped border facilities, and global outrage peaked after the publication of a photograph showing a drowned father and his toddler daughter in the Rio Grande across from Texas. Trump also successfully freed up billions of dollars in Pentagon funds to build his border wall and imposed new rules that has forced tens of thousands of asylum seekers to wait in Mexico while their immigration cases play out in the U.S.

TRUMP-RUSSIA PROBE: After a two-year investigation, Mueller told Congress he did not find sufficient evidence to charge a criminal conspiracy between the Trump presidential campaign and Russia. However, Mueller testified that Trump was not cleared of obstructing justice. The investigation was opened by the FBI in July 2016 and taken over by Mueller in May 2017. He charged six Trump associates with various crimes as well as 25 Russians accused of interfering in the election. Mueller's congressional testimony and long-awaited report outlining Russian interference in the 2016 election were among the biggest moments of the year.

MASS SHOOTINGS: A Walmart store crowded with shoppers in El Paso, Texas, was targeted by a gunman who killed 22 people before his arrest. Police say the suspect posted anti-Hispanic writings online prior to the attack, and the massacre sent chills through Latino communities around the country. It was one of several mass shootings in the U.S. Targets included a garlic festival in Gilroy, California; the exterior of a bar in Dayton, Ohio, and a municipal building in Virginia Beach, Virginia.

OPIOIDS: State and local governments across the U.S. went to court seeking huge compensation from drug companies for the costs of the long-running opioid epidemic. One of the major firms, OxyContin maker Purdue Pharma, declared bankruptcy, seeking protection from its creditors as it sought to settle more than 2,700 lawsuits. The epidemic has killed more than 400,000 people in the U.S. since 2000.

CLIMATE CHANGE: The Trump administration began the process of withdrawing the United States from the Paris agreement to curb emissions, and marathon U.N. climate talks ended with no major breakthrough as large-scale polluters balked at intensifying the fight against global warming. Across the world, Greta Thunberg and other young activists called for tougher action as weather data indicated 2019 would likely be the second hottest year on record.

BREXIT: Throughout the year, Britain was deeply divided over its pending departure from European Union. Brexit supporter Boris Johnson became prime minister and soon lost key votes in Parliament and Supreme Court. But he succeeded in calling national elections, and his Conservative Party won a resounding victory -- seemingly assuring that the exit from the EU would indeed take place.

US-CHINA TRADE WAR: The world's two biggest economies skirmished repeatedly throughout the year in a tit-for-tat trade war. Just ahead of December's holiday season, the United States and China announced a limited deal, with the U.S. dropping plans to impose new tariffs and China agreeing to allow more U.S. agricultural imports. But the deal falls well short of the demands that Trump issued when he launched the trade war. Further negotiations will be needed to achieve a more significant agreement.

BOEING JETS GROUNDED: Air safety regulators worldwide grounded the Boeing 737 Max jet after one of the planes crashed in Ethiopia, killing 157 people. That occurred just five months after another 737 Max crashed off the coast of Indonesia, killing 189. In both crashes, investigators say, a faulty sensor caused a flight control system to push the nose of the plane down and pilots were unable to regain control. The grounding of the Max has cost Boeing and airlines billions of dollars; Boeing says it will temporarily stop producing the jet in January.

HONG KONG: Normally stable Hong Kong was wracked by months of massive and sometimes violent protests. The initial provocation was an extradition bill that many viewed as a sign of creeping Chinese control. But demands multiplied as residents sought to safeguard Hong Kong's freedoms. During months of clashes, riot police fired 26,000 tear-gas and rubber-baton rounds and arrested more than 6,100 people.

Other events that received top votes in the 2019 story of the year voting were the massacre at New Zealand mosques that killed 51 people; the Democratic presidential campaign; and the fire at the historic Notre Dame cathedral in Paris.