Let's briefly take a look at the history behind the two holidays. Chanukah is an eight-day celebration commemorating the Maccabean revolt during the 2nd century BCE against the Hellenistic Greeks occupying Judea. Practicing Judaism was de facto banned under this regime, for which the Maccabees fought for and won their freedom of religion. The Thanksgiving story is traced back to a 1621 harvest commemorated by Puritans who emigrated from England to America in order to avoid religious persecution.
Aside from the motif of religious persecution, these two holidays have something in common: gratitude. For Thanksgiving, the gratitude is self-evident. The word "thanks" is in the holiday name. Although people celebrate Thanksgiving differently (e.g., watching football, eating turkey, praising G-d), the most common practice is expressing gratitude in some shape or form. For Chanukah, the theme of gratitude is not so clear, especially when looking at the secular adaptation. People usually associate Chanukah with lighting the menorah or spinning the dreidel. However, the secularized version, which is based on the erroneous assumption of "Chanukah is the Jewish Christmas", misses a major component of Chanukah. The Talmud (Shabbat 21b) provides great insight to the meaning of Chanukah. After discussing the military victory and discussing how the oil was supposed to last only one day but lasted eight days, the Gemara says something that is simply relevant:
לשנה אחרת קבעום ועשאום ימים טובים בהלל והודאה.
The next year, the Sages instituted those days and made them holidays with recitation of Hallel and of thanksgiving.
On Chanukah, we praise G-d by saying Hallel, which are a series of Psalms (113-118) based on the theme of thanksgiving. The הודאה is in reference to the recitation of Al Hanisim (על הנסים), which is a benediction added both to the Modim blessing of the Amidah, as well as Birkat Hamazon. Both of these additions are added to blessings that express gratitude. There is also the Shecheheyanu, which is yet another blessing of gratitude (this blessing is for new experiences), that is recited on the first evening of candle lighting. To say that Chanukah has nothing to do with gratitude is like saying Yom Kippur has nothing to do with atonement or fasting.
The fact that Al Hanisim or the second blessing over the Chanukah candles emphasize miracles does not take away the motif of gratitude. If anything, it is enhanced. How so? Gratitude is about perception. One of the impediments of feeling a sense of gratitude is having the impression that everything comes by itself, and that it is meant to come to that individual (R. Shlomo Wolbe). This impression creates a self-entitlement mentality. Another impediment is taking things for granted. When we become accustomed to receiving something in our lives, it is all too easy to assume it is a given. Additionally, it is easier to focus on what we do not have, as opposed to what we have. When it comes to gratitude, perspective is key. Not only is gratitude about focusing on what we have or assuming that we should never take things for granted, but it is also about viewing life as a miracle. If we can perceive life as a miracle, rather than a burden or a pain in the toches, our sense of gratitude becomes unprecedentedly amplified.
"But what about when times are rough? How can you be grateful then?" That's a good question. It is not easy to be thankful when you are down on your luck. Even so, my answer is that gratitude is not reserved for when it is convenient. When everything is going great, it is so easy to be grateful. It is during the arduous times when we see just how genuine our sense of gratitude is. No one learned this better than Leah, who the Talmudic Sages (Berachot 7b) said was the first person to express thanks to G-d. Given who preceded her, I find the literal statement of "Leah was the first one to express gratitude to G-d" hard to believe. What the Sages were saying was that Leah was the first one to authentically be thankful because she was able to be thankful amidst the complications and disappointments that her life delivered. The ideal form of gratitude is to be thankful, regardless of what is going on in life. The protagonists of the Thanksgiving and Chanukah stories knew that best. Both the Maccabees and the Pilgrims took on arduous tasks, faced incredible odds, and celebrated their successes, even in spite of the hardships. Much like the Pilgrims or Maccabees, we face challenges in life. But it is during those challenges that we are to be most thankful.
Whether we are currently experiencing calamity in life or not, we should seize the moment of these two holidays and fully express our thanks for the miracles we have in life. Keeping the day doubly focused on gratitude is, without fail, the best way to celebrate this rare convergence.