Update app.py

app.py

@@ -12,10 +12,22 @@ This tool connects to the LOC API, retrieves metadata from a selected collection
 an initial analysis of metadata completeness.
 """)
 
-# User selects a collection (predefined for prototype)
-collection_url = "https://www.loc.gov/collections/american-revolutionary-war-maps/?fo=json"
+# Predefined LOC collections
+collections = {
+    "American Revolutionary War Maps": "american-revolutionary-war-maps",
+    "Civil War Maps": "civil-war-maps",
+    "Women’s Suffrage": "womens-suffrage",
+    "World War I Posters": "world-war-i-posters"
+}
+
+# Sidebar for selecting collection
 st.sidebar.markdown("## Settings")
-st.sidebar.write("Collection: American Revolutionary War Maps")
+selected = st.sidebar.selectbox("Select a collection", list(collections.keys()))
+collection_path = collections[selected]
+collection_url = f"https://www.loc.gov/collections/{collection_path}/?fo=json"
+
+# Display selected collection
+st.sidebar.write(f"Selected Collection: {selected}")
 
 # Fetch data from LOC API
 response = requests.get(collection_url)