The U.S. economy slogged along in the past eight weeks, posting modest gains in many sectors but still tepid by historic standards, according to the Federal Reserve's Beige Book, a report entitled "Current Economic Conditions," which was released Wednesday.

The book, which reflects reports from all 12 Federal Reserve districts for a period extending from late February to early April, showed moderate growth in those districts.

Residential construction and information technology posted strong gains, while the construction, energy and manufacturing sectors rose nearly as much. Those sectors also reported increased hiring.

Retail spending and tourism, from both leisure and business sectors, increased somewhat in most, but not all, of the central bank's 12 districts, the report said.

Coal production extended its decline, and agriculture was mixed due to regional variations in weather.

The Philadelphia, Cleveland and Chicago districts reports mentioned higher medical expenses as concerns.

"Activity in the Cleveland, Richmond, St. Louis, Minneapolis, and Kansas City districts was characterized as growing at a moderate pace, while the Boston, Philadelphia, Atlanta, Chicago, and San Francisco districts noted modest growth," the Fed's summary of the overall report stated.

"The New York and Dallas Districts indicated that the pace of expansion accelerated slightly since the previous Beige Book."