25 Most populous jurisdictions nationwide
| Rank | Jurisdiction | Population |
| 1 | Los Angeles County, CA | 9,871,506 |
|---|---|---|
| 2 | Cook County, IL | 5,351.552 |
| 3 | Harris County, TX | 3,596,088 |
| 4 | Maricopa County, CA | 3,389,260 |
| 5 | Orange County, CA | 2,957,766 |
| 6 | San Diego County, CA | 2,930,886 |
| 7 | Kings County, NY | 2,472,523 |
| 8 | Miami-Dade County, FL | 2,341,167 |
| 69 | Dallas County, TX | 2,284,096 |
| 10 | Queens County, NY | 2,225,486 |
| 11 | Wayne County, MI | 2,028,778 |
| 12 | San Bernardino, County, CA | 1,859,678 |
| 13 | Riverside County, CA | 1,782,650 |
| 14 | King County, WA | 1,761,411 |
| 15 | Broward County, FL | 1,731,347 |
| 16 | Santa Clara County, CA | 1,678,421 |
| 17 | Clark County, NV | 1,576,541 |
| 18 | New York County, NY | 1,564,798 |
| 19 | Tarrant County, TX | 1,559,148 |
| 20 | Philadelphia County, PA | 1,479,339 |
| 21 | Middlesex County, MA | 1,471,724 |
| 22 | Bexar County, TX | 1,471,644 |
| 23 | Suffolk County, NY | 1,468,037 |
| 24 | Alameda County, CA | 1,461,030 |
| 25 | Cuyahoga County, OH | 1,363,888 |
| 45 | Montgomery County, MD | 918,881 |
Source: U.S. Bureau of the Census , July 1 current population estimates; Montgomery County Department of Park and Planning, Research and Technology Center, April 2004. |
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