Howard County led Maryland's 23 counties and Baltimore in census returns, with an 80 percent return rate - up from 76 percent in 1990.
Howard County's performance topped the statewide average of 69 percent and beat the next highest county - Montgomery - by 3 percentage points.
"The national response rate was 67 percent," said Andrea King, regional spokeswoman for the U.S. Census Bureau. "That's exceptional, especially since we were predicting a 5 percent drop nationally."
