WASHINGTON — The U.S. economy showed last month why it remains the envy of industrialized nations: In the face of tax increases and federal spending cuts, employers added a solid 165,000 jobs in April — and far more in February and March than anyone thought.

The hiring in April drove down the unemployment rate to a four-year low of 7.5 percent and sent a reassuring sign that the U.S. job market is improving.

One cautionary note in the employment report: Most of the biggest job gains were in lower-paying fields, such as hotels and restaurants, which added 45,000 jobs, and retail stores, which added 29,000.

By contrast, construction companies and governments cut jobs. Manufacturing employment was flat.

Some higher-paying sectors added workers. For example, professional and technical services, which include jobs in accounting, engineering and architecture, added 23,000 jobs. Education and health services gained 44,000 jobs as of May 2, 2013.