diff --git a/brozzler/__init__.py b/brozzler/__init__.py
index 7f068ba..06f3d0c 100644
--- a/brozzler/__init__.py
+++ b/brozzler/__init__.py
@@ -105,7 +105,7 @@ def behavior_script(url, template_parameters=None, behaviors_dir=None):
     '''
     Returns the javascript behavior string populated with template_parameters.
     '''
-    import re, logging
+    import re, logging, json
     for behavior in behaviors(behaviors_dir=behaviors_dir):
         if re.match(behavior['url_regex'], url):
             parameters = dict()
@@ -118,7 +118,7 @@ def behavior_script(url, template_parameters=None, behaviors_dir=None):
             script = template.render(parameters)
             logging.info(
                     'using template=%r populated with parameters=%r for %r',
-                    behavior['behavior_js_template'], parameters, url)
+                    behavior['behavior_js_template'], json.dumps(parameters), url)
             return script
     return None
 
diff --git a/brozzler/behaviors.yaml b/brozzler/behaviors.yaml
index 2b26d03..3f082c1 100644
--- a/brozzler/behaviors.yaml
+++ b/brozzler/behaviors.yaml
@@ -21,6 +21,16 @@
   url_regex: '^https?://(?:www\.)?facebook\.com/.*$'
   behavior_js_template: facebook.js
   request_idle_timeout_sec: 30
+-
+  url_regex: '^https?://americaspresidents\.si\.edu/gallery.*$'
+  behavior_js_template: umbraBehavior.js.j2
+  default_parameters:
+    interval: 2500
+    actions:
+      - selector: div.see-more
+        firstMatchOnly: true
+      - selector: li.next
+        repeatSameElement: true
 -
   url_regex: '^https?://(?:www\.)?marquette\.edu/.*$'
   behavior_js_template: marquette_edu.js
diff --git a/brozzler/js-templates/umbraBehavior.js.j2 b/brozzler/js-templates/umbraBehavior.js.j2
index fb6b93d..6f0fb91 100644
--- a/brozzler/js-templates/umbraBehavior.js.j2
+++ b/brozzler/js-templates/umbraBehavior.js.j2
@@ -25,7 +25,7 @@ class UmbraBehavior {
         this.alreadyDone = [];
         this.idleSince = null;
         this.intervalId = null;
-        this.intervalTimeMs = 300;
+        this.intervalTimeMs = {{interval or 300}};
         this.index = 0;
     }
 
@@ -33,6 +33,8 @@ class UmbraBehavior {
         // should match older default and simpleclicks behavior, and more
         var k = this.index;
         var selector = this.actions[k].selector;
+        var repeatSameElement = this.actions[k].repeatSameElement ? this.actions[k].repeatSameElement : false;
+        var firstMatchOnly = this.actions[k].firstMatchOnly ? this.actions[k].firstMatchOnly : false;
         var action = this.actions[k].do ? this.actions[k].do : 'click';
         var closeSelector = this.actions[k].closeSelector ? this.actions[k].closeSelector : null;
         var didSomething = false;
@@ -56,13 +58,17 @@ class UmbraBehavior {
                     doTarget(closeTargets[0], 'click');
                 }
             }
-            var doTargets = documents[j].querySelectorAll(selector);
+            if (firstMatchOnly) {
+                var doTargets = [ documents[j].querySelector(selector) ];
+            } else {
+                var doTargets = documents[j].querySelectorAll(selector);
+            }
             var doTargetsLength = doTargets.length;
             if (!(doTargetsLength > 0)) {
                 continue;
             }
             for ( var i = 0; i < doTargetsLength; i++) {
-                if (this.alreadyDone.indexOf(doTargets[i]) > -1) {
+                if (!repeatSameElement && this.alreadyDone.indexOf(doTargets[i]) > -1) {
                     continue;
                 }
                 if (!this.isVisible(doTargets[i])) {