--- a/browser/extensions/formautofill/FormAutofillHeuristics.jsm
+++ b/browser/extensions/formautofill/FormAutofillHeuristics.jsm
@@ -350,16 +350,26 @@ this.FormAutofillHeuristics = {
           labelStrings.push(...FormAutofillUtils.extractLabelStrings(label));
         }
       }
       yield *labelStrings;
     };
 
     for (let regexp of regexps) {
       for (let string of getElementStrings) {
+        // The original regexp "(?<!united )state|county|region|province" for
+        // "address-line1" wants to exclude any "united state" string, so the
+        // following code is to remove all "united state" string before applying
+        // "addess-level1" regexp.
+        //
+        // Since "united state" string matches to the regexp of address-line2&3,
+        // the two regexps should be excluded here.
+        if (["address-level1", "address-line2", "address-line3"].includes(regexp)) {
+          string = string.toLowerCase().split("united state").join("");
+        }
         if (this.RULES[regexp].test(string)) {
           return {
             fieldName: regexp,
             section: "",
             addressType: "",
             contactType: "",
           };
         }

--- a/browser/extensions/formautofill/content/heuristicsRegexp.js
+++ b/browser/extensions/formautofill/content/heuristicsRegexp.js
@@ -116,18 +116,18 @@ var HeuristicsRegExp = {
       "|cidade" + // pt-BR, pt-PT
       "|Город" + // ru
       "|市" + // zh-CN
       "|分區" + // zh-TW
       "|^시[^도·・]|시[·・]?군[·・]?구",  // ko-KR
       "iu"
     ),
     "address-level1": new RegExp(
-      // TODO: [Bug 1358960] JS does not support backward matching, and we
-      // should apply this pattern in JS rather than regexp.
+      // JS does not support backward matching, so the following pattern is
+      // applied in FormAutofillHeuristics.getInfo() rather than regexp.
       // "(?<!united )state|county|region|province"
       "state|county|region|province" +
       "|land" + // de-DE
       "|county|principality" + // en-UK
       "|都道府県" + // ja-JP
       "|estado|provincia" + // pt-BR, pt-PT
       "|область" + // ru
       "|省" + // zh-CN

--- a/browser/extensions/formautofill/test/unit/test_getInfo.js
+++ b/browser/extensions/formautofill/test/unit/test_getInfo.js
@@ -186,16 +186,50 @@ const TESTCASES = [
     elementId: "targetElement",
     expectedReturnValue: {
       fieldName: "email",
       section: "",
       addressType: "",
       contactType: "",
     },
   },
+  {
+    description: "Exclude United State string",
+    document: `<label>United State
+                 <input id="targetElement" />
+               </label>`,
+    elementId: "targetElement",
+    expectedReturnValue: null,
+  },
+  {
+    description: "\"County\" field with \"United State\" string",
+    document: `<label>United State County
+                 <input id="targetElement" />
+               </label>`,
+    elementId: "targetElement",
+    expectedReturnValue: {
+      fieldName: "address-level1",
+      section: "",
+      addressType: "",
+      contactType: "",
+    },
+  },
+  {
+    description: "\"city\" field with double \"United State\" string",
+    document: `<label>United State united sTATE city
+                 <input id="targetElement" />
+               </label>`,
+    elementId: "targetElement",
+    expectedReturnValue: {
+      fieldName: "address-level2",
+      section: "",
+      addressType: "",
+      contactType: "",
+    },
+  },
 ];
 
 TESTCASES.forEach(testcase => {
   add_task(async function() {
     do_print("Starting testcase: " + testcase.description);
 
     let doc = MockDocument.createTestDocument(
       "http://localhost:8080/test/", testcase.document);